Droplet sorting system, droplet sorting method

Abstract

The application relates to the technical field of cell sorting, and discloses a droplet sorting system, which comprises a flow channel assembly, a fluorescence signal detection device and a sorting device. The flow channel assembly defines a droplet flow channel for droplet flow, a first liquid outlet flow channel and a second liquid outlet flow channel. The fluorescence signal detection device is used for exciting droplets to emit fluorescence and marking droplets meeting fluorescence conditions as target droplets. The sorting device is arranged corresponding to the liquid outlet section of the droplet flow channel. Target droplets flowing through the liquid outlet section of the droplet flow channel enter the first liquid outlet flow channel under the deflection of the sorting device, and non-target droplets enter the second liquid outlet flow channel. The application also discloses a droplet sorting method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cell sorting, for example to a droplet sorting system and a droplet sorting method. BACKGROUND

[0002] Antibodies are one of the important humoral immune mechanisms of the body to resist the invasion of pathogens such as viruses and bacteria. Protective vaccines are an important weapon to curb the spread of various pathogens, which can not only specifically recognize pathogens, but also closely combine with antigens, thereby effectively blocking the damage of pathogens to cells, tissues and organisms. Antibodies are produced by B cells, and are screened layer by layer through the lymphatic system, and only a small number of B cells with gene rearrangement produce high-affinity antibodies. How to effectively separate and enrich B cells secreting high-affinity antibodies is a difficulty in the field of antibody research.

[0003] The related technology discloses a system for detecting, sorting and dispensing droplets for biological assays, the system comprising: a microfluidic device comprising a first channel connected to a second channel and a waste channel by a first sorting junction; a plurality of water-in-oil droplets, wherein at least two of the plurality of water-in-oil droplets each comprise at least one cell, at least one particle, or at least one cell plus at least one particle; a first detector or sensor corresponding to a first detection point disposed along the first channel upstream of the sorting junction, wherein the first detector comprises an optical detector; a second detector or sensor corresponding to a second detection point disposed along the second channel downstream of the sorting junction; a target droplet dispensing module comprising a dispensing nozzle disposed downstream of the second detection point; and a processor configured to index each of a plurality of target droplets dispensed by the dispensing nozzle with a first signal of the same target droplet detected at the first detection point by the first detector or sensor, a second signal of the same target droplet detected at the second detection point by the second detector or sensor, or both the first signal and the second signal.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0005] In the related art, when the droplet flows through the first detection point or the second detection point, the particles in the droplet need to be arranged in a certain rule by a magnet, a magnet pair or a magnet array so that the characteristics of the particles become obvious. The magnetic particles in the droplet are magnetized near the monitoring point and arranged under the action of the magnetic field force. The particles in the droplet interact with the nearby particles to form a line. In the case that the distribution of the magnets in the droplet is relatively dispersed, the particles in the droplet are rearranged into multiple fine lines. In the case that the distribution of the magnets in the droplet is relatively dispersed, the particles in the droplet are rearranged into multiple fine lines in the magnetic field. In the case that the particles in the droplet are arranged into multiple fine lines, when the droplet is identified by fluorescence, the characteristic peak of the fluorescence signal is not obvious, which affects the recognition accuracy of the cells.

[0006] In the related art, a microfluidic chip device and a use method based on a magnetic field control sorting fluorescently labeled cell method are also disclosed. The microfluidic chip includes a sample channel, two sheath liquid channels, a first fluorescent detection area, a second fluorescent detection area, a magnetic field control system, a magnetic field control cell sorting area, a target cell channel and a waste liquid channel. The sample channel and the two sheath liquid channels are connected and communicate with each other, and the sample channel is located between the two sheath liquid channels. The connection pipelines of the sample channel and the two sheath liquid channels are respectively a first flow channel and a second flow channel. The first flow channel and the second flow channel cross the two sheath liquid channels at a first intersection point and a second intersection point respectively. The target cell channel starts from the first intersection point, and the waste liquid channel starts from the second intersection point. The magnetic field control cell sorting area is arranged on the first flow channel and the second flow channel, and the cell sorting area includes a magnetic sub. The magnetic sub is controlled by the magnetic field control system to move back and forth on the first flow channel and the second flow channel to control the flow direction of the sample. When the magnetic sub is located in the first flow channel, the sample channel is connected and communicated with the waste liquid channel. When the magnetic sub is located in the second flow channel, the sample channel is connected and communicated with the target cell channel. The droplet is controlled to flow to the waste liquid channel and the target cell channel by the movement of the magnetic sub.

[0007] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

[0008] In the related art, if the magnetic particles are used to enrich the antigens and the secondary antibodies in the droplet, the magnetic particles in the droplet will be adhered to the magnetic sub when the droplet is located near the magnetic sub, which affects the sorting effect of the cells. As a moving part in the flow channel, the magnetic sub has the risk of crushing the cells during the movement.

[0009] In addition, in the related art, a single set of electrode pairs is arranged to apply an electrophoretic force to the droplet to deflect the droplet. In this case, the droplet may be broken due to a relatively large local force.

[0010] In addition, only by electrophoretic force or electric field force or magnetic field force to drive the droplet deflection into the target flow channel, the flux of cell sorting is low, and the droplet may be damaged at the same time.

[0011] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0012] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to determine the key / important components or delineate the scope of protection of these embodiments, but as a prelude to the detailed description that follows.

[0013] The embodiments of the present disclosure provide a droplet sorting system and a droplet sorting method to solve at least one problem existing in the related art.

[0014] In some embodiments, the droplet sorting system includes a flow channel assembly, a fluorescence signal detection device, and a sorting device, wherein the flow channel assembly defines a droplet flow channel for the flow of droplets, a first droplet outlet flow channel, and a second droplet outlet flow channel; the fluorescence signal detection device is used to excite the droplets to emit fluorescence and mark the droplets meeting the fluorescence condition as target droplets; the sorting device is arranged corresponding to the outlet section of the droplet flow channel, and the target droplets flowing through the outlet section of the droplet flow channel enter the first droplet outlet flow channel under the deflection of the sorting device, and the non-target droplets enter the second droplet outlet flow channel.

[0015] In some embodiments, the sorting device includes a sorting electromagnet, which is arranged at the outlet section of the droplet flow channel, and the sorting electromagnet is started when the target droplets flow through the outlet section of the droplet flow channel to deflect the target droplets to the first droplet outlet flow channel under the action of the magnetic field force.

[0016] In some embodiments, the sorting device includes a first air pump, which is arranged at the first droplet outlet flow channel, and the first air pump is configured to apply positive pressure to the first droplet outlet flow channel when the non-target droplets flow through the outlet section of the droplet flow channel.

[0017] In some embodiments, the sorting device includes a second air pump, which is arranged at the second droplet outlet flow channel, and the second air pump is configured to apply positive pressure to the second droplet outlet flow channel when the target droplets flow through the sorting device.

[0018] In some embodiments, the sorting device further comprises a positive electrode and a negative electrode, the positive electrode and the negative electrode are arranged on the same side of the droplet flow channel, and the positive electrode and the negative electrode form an electric field acting on the droplet flow channel when energized, and the target droplet deflects to the first outlet flow channel under the action of the electrophoretic force.

[0019] In some embodiments, the sorting device further comprises a positive electrode and a negative electrode, the positive electrode is arranged on the side of the first outlet flow channel of the droplet flow channel, and the negative electrode is arranged on the side of the first outlet flow channel of the droplet flow channel, and the positive electrode and the negative electrode form an electric field acting on the droplet flow channel when energized, and the target droplet deflects to the first outlet flow channel under the action of the electrophoretic force.

[0020] In some embodiments, the sorting device comprises a plurality of positive electrodes and a plurality of negative electrodes, the plurality of positive electrodes and the plurality of negative electrodes are arranged alternately, and the plurality of negative electrodes are connected.

[0021] In some embodiments, the sorting device comprises a plurality of positive electrodes and two negative electrodes, and the two negative electrodes are respectively located on the two sides of the plurality of positive electrodes.

[0022] In some embodiments, the sorting device comprises a plurality of positive electrodes, and distances between the plurality of positive electrodes and the droplet flow channel are not completely the same.

[0023] In some embodiments, the sorting device comprises an electrode assembly, and the electrode assembly comprises at least one electrode unit arranged on one side of the droplet flow channel, wherein the electrode unit comprises one or more positive electrodes and two negative electrodes, the positive electrodes are arranged on the first side of the droplet flow channel, and the two negative electrodes are arranged on the first side of the droplet flow channel and respectively located on the two sides of the one or more positive electrodes.

[0024] In some embodiments, the electrode unit comprises a plurality of positive electrodes, and the two negative electrodes are respectively located on the two sides of the plurality of positive electrodes.

[0025] In some embodiments, along the droplet flow direction, distances between the plurality of positive electrodes and the droplet flow channel gradually increase.

[0026] In some embodiments, along the droplet flow direction, voltages of the plurality of positive electrodes gradually decrease.

[0027] In some embodiments, the electrode assembly comprises a plurality of electrode units, and the plurality of electrode units are arranged on the first side of the droplet flow channel.

[0028] In some embodiments, along the droplet flow direction, distances between the plurality of electrode units and the droplet flow channel gradually increase.

[0029] In some embodiments, along the droplet flow direction, voltages of the positive electrodes of the plurality of electrode units gradually decrease.

[0030] In some embodiments, two adjacent electrode units share one negative electrode.

[0031] In some embodiments, the electrode unit comprises one positive electrode and two negative electrodes, and the positive electrodes and the negative electrodes of the electrode assembly are arranged alternately.

[0032] In some embodiments, the positive electrodes and the negative electrodes of the electrode assembly are arranged alternately at equal intervals.

[0033] In some embodiments, the negative electrodes of the electrode assembly are connected in communication, and the positive electrodes of the electrode assembly are independently controlled to be conductive.

[0034] In some embodiments, the electrode assembly further comprises a first shielding electrode, which is arranged on the second side of the droplet flow channel and opposite to the electrode unit.

[0035] In some embodiments, the first shielding electrode is in communication with the negative electrodes of the electrode unit.

[0036] In some embodiments, the electrode assembly further comprises a second shielding electrode, which is arranged on the first side of the droplet flow channel, and is arranged on the circumferential outer side of the electrode unit and surrounds the electrode unit.

[0037] In some embodiments, the second shielding electrode is in communication with the negative electrodes of the electrode unit.

[0038] In some embodiments, the positive electrodes and the negative electrodes of the electrode unit are connected to the power supply through a high-voltage isolation pulse transformer.

[0039] In some embodiments, the sorting device comprises the electrode assembly and the control device described above, and the control device is configured to control the plurality of positive electrodes of the electrode assembly to be sequentially energized when the target droplet flows through the electrode assembly.

[0040] In some embodiments, the control device comprises an acquisition module, a determination module and a control module, wherein the acquisition module is configured to acquire the flow rate of the target droplet; the determination module is configured to determine the first time when the target droplet flows through the working area of the electrode assembly according to the flow rate of the target droplet; and the control module is configured to control the plurality of positive electrodes of the electrode assembly to be sequentially energized from the first time.

[0041] In some embodiments, the acquisition module comprises a determination unit and a first calculation unit, wherein the determination unit is configured to determine the first time length required for the droplet to flow through the fluorescence signal detection device according to the wave width of the fluorescence signal; and the first calculation unit is configured to determine the flow rate of the droplet according to the first time length and the working length of the fluorescence signal detection device.

[0042] In some embodiments, the acquisition module comprises a photographing control unit, a comparison unit and a second calculation unit, wherein the photographing control unit is configured to control the high-speed camera to continuously photograph the droplet images at intervals of the second time length; the comparison unit is configured to compare the continuously photographed droplet images to determine the displacement distance of the droplet; and the second calculation unit is configured to determine the flow rate of the droplet according to the displacement distance of the droplet and the second time length.

[0043] In some embodiments, the control module comprises a third calculation unit and a first execution unit, wherein the third calculation unit is configured to determine the energization interval of the electrodes according to the flow rate of the target droplet; and the first execution unit is configured to control the plurality of electrodes of the electrode assembly to be energized one by one at the energization interval starting from the first time point.

[0044] In some embodiments, the control module comprises a fourth calculation unit and a second execution unit, wherein the fourth calculation unit is configured to determine the target voltage of the plurality of electrodes according to the flow rate of the target droplet; and the second execution unit is configured to control the plurality of electrodes of the electrode assembly to be energized one by one at the determined energization voltage starting from the first time point.

[0045] In some embodiments, the flow channel assembly further comprises a microfluidic chip, the microfluidic chip defines a positive electrode flow channel and a negative electrode flow channel, the positive electrode flow channel is filled with a conductive medium to form a positive electrode, and the negative electrode flow channel is filled with a conductive medium to form a negative electrode, the positive electrode comprises the positive electrode, and the negative electrode comprises the negative electrode.

[0046] In some embodiments, the conductive medium is metal, and the metal conductive medium is filled into the positive electrode flow channel and / or the negative electrode flow channel in a liquid form.

[0047] In some embodiments, when the electrode assembly further comprises a first shielding electrode, the microfluidic chip further defines a first shielding electrode flow channel, the first shielding electrode flow channel is filled with a conductive medium to form a first shielding electrode, and the negative electrode flow channel is further communicated with the first shielding electrode flow channel.

[0048] In some embodiments, when the electrode assembly further comprises a second shielding electrode, the microfluidic chip further defines a second shielding electrode flow channel, the second shielding electrode flow channel is filled with a conductive medium to form a second shielding electrode, and the negative electrode flow channel is further communicated with the second shielding electrode flow channel.

[0049] In some embodiments, the microfluidic chip further defines a connecting flow channel, a first end of the connecting flow channel is connected to the first shielding electrode flow channel, a second end of the connecting flow channel is connected to the second shielding electrode flow channel, the second shielding electrode flow channel is directly communicated with the negative electrode flow channel, and the first shielding electrode flow channel is communicated with the negative electrode flow channel through the connecting flow channel.

[0050] In some embodiments, the flow channel assembly comprises a microfluidic chip, the microfluidic chip defining the droplet flow channel, the first outlet flow channel and the second outlet flow channel inside the microfluidic chip.

[0051] In some embodiments, the microfluidic chip further defines a sheath liquid inflow channel and a sample liquid inflow channel, the sample liquid inflow channel having an inflow end for filling the liquid droplet pre-magnetized by a magnetic field, the outflow end of the sample liquid inflow channel and the outflow end of the sheath liquid inflow channel being in communication with the inflow end of the droplet flow channel, the liquid droplet pre-magnetized by the magnetic field being mixed with the sheath liquid and entering the droplet flow channel.

[0052] In some embodiments, the microfluidic chip further defines a positive electrode flow channel and a negative electrode flow channel, the positive electrode flow channel being filled with a conductive medium to form a positive electrode, and / or the negative electrode flow channel being filled with a conductive medium to form a negative electrode.

[0053] In some embodiments, the positive electrode flow channel is located on one side of the droplet flow channel, and the negative electrode flow channel is located on the other side of the droplet flow channel.

[0054] In some embodiments, the conductive medium is metal, and the metal conductive medium is filled into the electrode flow channel in a liquid form.

[0055] In some embodiments, the flow channel assembly further comprises a support frame, the support frame comprising a bottom plate, a first side plate and a second side plate, the first side plate and the second side plate being oppositely arranged; wherein the microfluidic chip is located between the first side plate and the second side plate and is lapped on the upward side of the bottom plate.

[0056] In some embodiments, the sorting device further comprises an electrode mounting plate, a positive electrode connecting piece and a negative electrode connecting piece, the electrode mounting plate being fixed to the first side plate and / or the second side plate of the support frame, the positive electrode connecting piece being fixed to the electrode mounting plate and extending towards the microfluidic chip, the positive electrode connecting piece being used to connect the positive electrode to a power supply; the negative electrode connecting piece being fixed to the electrode mounting plate and extending towards the microfluidic chip, the negative electrode connecting piece being used to connect the negative electrode to a power supply. In some embodiments, the fluorescence signal detection device comprises a laser assembly and a fluorescence detection assembly, wherein the laser assembly is used to emit laser to the magnetic particles pulled into a linear shape, and the fluorescent markers in the liquid droplet are excited by the laser to emit fluorescence; the fluorescence detection assembly is used to detect the fluorescence emitted by the fluorescent markers in the liquid droplet.

[0057] In some embodiments, the laser assembly comprises a first laser source configured to emit laser light of a first wavelength, one of the antigen and the secondary antibody is configured to emit fluorescent light of the first wavelength when excited by the laser light of the first wavelength; and the fluorescent light detection assembly comprises a first fluorescent light detector configured to detect the fluorescent light of the first wavelength.

[0058] In some embodiments, the laser assembly further comprises a second laser source configured to emit laser light of a second wavelength, another of the antigen and the secondary antibody is configured to emit fluorescent light of the second wavelength when excited by the laser light of the second wavelength; and the fluorescent light detection assembly further comprises a second fluorescent light detector configured to detect the fluorescent light of the second wavelength.

[0059] In some embodiments, the laser assembly further comprises a coaxial system configured to direct the laser light of the first wavelength and the laser light of the second wavelength to the droplet in the droplet flow channel, and configured to direct the fluorescent light of the first wavelength and the fluorescent light of the second wavelength in the droplet flow channel to the first fluorescent light detector and the second fluorescent light detector.

[0060] In some embodiments, the droplet sorting system further comprises a fluorescent signal identification device, the fluorescent signal identification device comprises a light source assembly and an imaging assembly, the light emitting direction of the light source assembly is towards the droplet in the first magnetic field; the imaging position of the imaging assembly is towards the droplet in the first magnetic field.

[0061] In some embodiments, the imaging assembly comprises a high-speed camera, the lens of the high-speed camera is towards the droplet in the first magnetic field, and the shutter of the high-speed camera is synchronized to open with the light source assembly.

[0062] In some embodiments, the droplet sorting system further comprises a fluorescent signal enhancement device, the fluorescent signal enhancement device is configured to enhance the fluorescent signal of the magnetic particles in the droplet.

[0063] In some embodiments, the fluorescent signal enhancement device comprises a magnet assembly configured to generate the first magnetic field, and the magnetic particles in the droplet are pulled into a linear shape in the first magnetic field.

[0064] In some embodiments, the fluorescent signal enhancement device further comprises a pre-magnetization assembly configured to generate the pre-magnetization magnetic field, and the magnetic particles in the droplet are magnetized and aggregated in the pre-magnetization magnetic field, and the aggregated magnetic particles are pulled into a linear shape in the first magnetic field.

[0065] In some embodiments, the magnetic field strength of the pre-magnetization magnetic field is greater than the magnetic field strength of the first magnetic field.

[0066] In some embodiments, the pre-magnetization assembly comprises a pre-magnetization pipe and a pre-magnetization magnet, the pre-magnetization pipe defines a pre-magnetization flow path for the liquid droplet to flow; the pre-magnetization magnet is configured to generate a pre-magnetization magnetic field, at least a portion of the pre-magnetization flow path is located in the pre-magnetization magnetic field.

[0067] In some embodiments, the pre-magnetization flow path is connected to the liquid droplet flow path, and the liquid droplet flow path is located at a rear stage of the pre-magnetization flow path along the liquid droplet flow direction.

[0068] In some embodiments, the pre-magnetization magnet comprises a first pre-magnetization magnet and a second pre-magnetization magnet, wherein the first pre-magnetization magnet is arranged on one side of the pre-magnetization pipe; and the second pre-magnetization magnet is arranged on the other side of the pre-magnetization pipe.

[0069] In some embodiments, the pre-magnetization magnet comprises a pre-magnetization coil, the pre-magnetization coil is wound around the pre-magnetization pipe, the axis of the pre-magnetization coil is along the length direction of the pre-magnetization pipe, and the pre-magnetization coil generates the pre-magnetization magnetic field when energized.

[0070] In some embodiments, the pre-magnetization magnet is configured to generate a pre-magnetization magnetic field with a direction change, and the magnetic particles in the liquid droplet move and agglomerate in the pre-magnetization flow path under the action of the magnetic force of the changing magnetic field.

[0071] In some embodiments, the pre-magnetization magnet comprises a plurality of magnet pairs, the plurality of magnet pairs are arranged close to the pre-magnetization flow path, a magnetic induction line is formed between each magnet pair, and the magnetic induction lines of the plurality of magnet pairs are different in direction to form the pre-magnetization magnetic field with the direction change.

[0072] In some embodiments, the pre-magnetization magnet comprises an electromagnet, and the pre-magnetization magnetic field with the direction change is formed by adjusting the current intensity and / or current direction of the electromagnet; or, the pre-magnetization magnet comprises a coil, the coil is wound around the pre-magnetization pipe, the pre-magnetization coil generates the pre-magnetization magnetic field when energized, and the pre-magnetization magnetic field with the direction change is formed by adjusting the current intensity and / or current direction of the coil.

[0073] In some embodiments, the pre-magnetization flow path is a flow path with a direction change, at least a portion of the flow path with the direction change is located in the pre-magnetization magnetic field, and the magnetic particles in the liquid droplet move and agglomerate in the flow path with the direction change under the action of the magnetic force of the first magnetic field.

[0074] In some embodiments, the pre-magnetization flow path comprises a plurality of bending sections, and the plurality of bending sections are connected in series to form the flow path with the direction change.

[0075] In some embodiments, the pre-magnetization flow path is a spiral flow path.

[0076] In some embodiments, the pre-magnetization conduit is wound around the pre-magnetization magnet to form the directionally changing flow path.

[0077] In some embodiments, the pre-magnetization magnetic field comprises a first portion and a second portion, the magnetic field direction of the first portion remains unchanged, and the magnetic field direction of the second portion changes over time.

[0078] In some embodiments, the pre-magnetization magnet comprises an alternating current electromagnet, and the alternating current electromagnet generates the second portion of the pre-magnetization magnetic field when energized.

[0079] In some embodiments, the pre-magnetization magnet comprises a direct current electromagnet, and the direct current electromagnet generates the first portion of the pre-magnetization magnetic field when energized.

[0080] In some embodiments, the pre-magnetization conduit is a flexible hose, and the length of the portion of the pre-magnetization flow path located in the pre-magnetization magnetic field is adjusted by moving the pre-magnetization conduit.

[0081] In some embodiments, the droplet sorting method comprises: applying a laser to the droplet to cause a fluorescent marker combined with the magnetic particles in the droplet to emit light; marking the droplet meeting the fluorescent condition as a target droplet; and applying a deflection force to the target droplet to deflect the droplet to a target droplet flow path.

[0082] In some embodiments, before the laser is applied to the droplet to cause the fluorescent marker combined with the magnetic particles in the droplet to emit light, the method further comprises: applying a magnetic field to the droplet to pull the agglomerated magnetic particles into a linear shape.

[0083] In some embodiments, before the magnetic field is applied to the droplet to pull the agglomerated magnetic particles into a linear shape, the method further comprises: pre-magnetizing the droplet to agglomerate the magnetic particles in the droplet.

[0084] In some embodiments, the deflection force is applied to the target droplet to deflect the end of the target droplet to the target flow path, comprising: sequentially activating a plurality of electrodes arranged in the direction of droplet flow to apply electrophoretic force to the target droplet multiple times to deflect the target droplet to the target flow path.

[0085] In some embodiments, the target flow path is connected to a first air pump, and the deflection force is applied to the target droplet to deflect the end of the target droplet to the target flow path, comprising: activating the first air pump to apply positive pressure to the target flow path to deflect the non-target droplet to a non-target flow path in the case that the non-target droplet pre-enters the target flow path.

[0086] In some embodiments, the non-target flow path is connected to a second air pump, and the deflection force is applied to the target droplet to deflect the end of the target droplet to the target flow path, comprising: activating the second air pump to apply positive pressure to the non-target flow path to deflect the target droplet to the target flow path in the case that the target droplet pre-enters the non-target flow path.

[0087] In some embodiments, the at least one cell, the plurality of magnetic particles, the plurality of antibodies specifically binding to the magnetic particles, the plurality of antigens specifically binding to the antibodies, and / or the secondary antibodies in the droplet are each fluorescently dyed; the method of applying laser to the droplet to make the fluorescent markers in the droplet that are bound to the magnetic particles emit light comprises: applying a first laser and a second laser to the linear magnetic particles to make the first fluorescent markers and the second fluorescent markers in the droplet that are bound to the magnetic particles emit light; and the method of marking the droplet meeting the fluorescent condition as a target droplet comprises: marking the droplet whose first fluorescent signal meets the first condition and whose second fluorescent signal meets the second condition as the target droplet.

[0088] In some embodiments, the second condition is determined according to the first condition.

[0089] In some embodiments, after marking the droplet whose first fluorescent signal meets the first condition and whose second fluorescent signal meets the second condition as the target droplet, the method of sorting the droplet further comprises: obtaining a first time when the target droplet flows through the imaging position; and starting the imaging assembly at the first time to obtain an image of the target droplet.

[0090] In some embodiments, after calculating the first time when the target droplet flows through the imaging position, the method of sorting the droplet further comprises: starting the light source assembly to supplement light for the imaging assembly at the first time.

[0091] The droplet sorting system and the method of sorting the droplet provided by the embodiments of the present disclosure can achieve the following technical effects:

[0092] The fluorescent signal detection device can accurately identify the target droplet. After the target droplet is identified, the sorting device applies a deflection force to the target droplet so that the target droplet can be deflected to the first liquid outlet flow channel. The sorting of the droplet does not need to be performed by setting a moving component on the path of the droplet flow, thereby reducing or avoiding the sample such as cells, bacteria, etc. in the droplet from being crushed by the moving component.

[0093] Further, by setting the pre-magnetization assembly, the magnetic particles can be magnetized before entering the first magnetic field to form an agglomeration state. The magnetized and agglomerated magnetic particles can be pulled into a linear shape after entering the first magnetic field, so that the fluorescent substances in the particle group can be more fully excited by the laser, thereby improving the identification accuracy of the droplet. The pressure difference generated by the first air pump and / or the second air pump drives the controlled movement of the droplet. The path of the droplet flow does not set a magnetic component, and the droplet flow will not be adhered to the magnetic component.

[0094] The general description above and the following description below are exemplary and explanatory only and are not intended to be limiting. BRIEF DESCRIPTION OF DRAWINGS

[0095] One or more embodiments are illustrated by way of example in the figures that are not intended to be limiting of the embodiments. Like numbers refer to like elements throughout the drawings, which are not necessarily to scale, and in which:

[0096] Figure 1 is a structural schematic diagram of a droplet sorting system provided by an embodiment of the present disclosure;

[0097] Figure 2 is a structural schematic diagram of another droplet sorting system provided by an embodiment of the present disclosure;

[0098] Figure 3 is a structural schematic diagram of another droplet sorting system provided by an embodiment of the present disclosure;

[0099] Figure 4 is Figure 3 is an enlarged schematic diagram of A in FIG. 1;

[0100] Figure 5 is a structural schematic diagram of a fluorescence signal enhancement device of a droplet sorting system provided by an embodiment of the present disclosure;

[0101] Figure 6 is a structural schematic diagram of a fluorescence signal enhancement device of another droplet sorting system provided by an embodiment of the present disclosure;

[0102] Figure 7 is a structural schematic diagram of a fluorescence signal enhancement device of another droplet sorting system provided by an embodiment of the present disclosure;

[0103] Figure 8 is a structural schematic diagram of a fluorescence signal enhancement device of another droplet sorting system provided by an embodiment of the present disclosure;

[0104] Figure 9 is a microstructure diagram of a droplet that has not been pre-magnetized;

[0105] Figure 10 is a microstructure diagram of a droplet after pre-magnetization;

[0106] Figure 11 is a microstructure diagram of a droplet that has not been pre-magnetized in a first magnetic field;

[0107] Figure 12 is a microstructure diagram of a pre-magnetized droplet in a first magnetic field;

[0108] Figure 13 is a fluorescence signal intensity diagram of a droplet in a first magnetic field, in which the left side is the fluorescence signal intensity when the droplet is not pre-magnetized, and the right side is the fluorescence signal intensity after pre-magnetization of the droplet;

[0109] Figure 14 is a structural schematic diagram of an electrode assembly provided by an embodiment of the present disclosure;

[0110] Figure 15 is a structural schematic diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0111] Figure 16 is a structural schematic diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0112] Figure 17 is a structural schematic diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0113] Figure 18 is a structural schematic diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0114] Figure 19 is a structural schematic diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0115] Figure 20 is a schematic diagram of a droplet sorting method provided by an embodiment of the present disclosure;

[0116] Figure 21 is a schematic diagram of another droplet sorting method provided by an embodiment of the present disclosure;

[0117] Figure 22 is a schematic diagram of another droplet sorting method provided by an embodiment of the present disclosure;

[0118] Figure 23 is a schematic diagram of another droplet sorting method provided by an embodiment of the present disclosure;

[0119] Figure 24 is a schematic diagram of another droplet sorting method provided by an embodiment of the present disclosure;

[0120] Figure 25 is a schematic diagram of a fluorescence signal detection method provided by an embodiment of the present disclosure;

[0121] Figure 26 is a schematic diagram of an apparatus for controlling a droplet sorting system provided by an embodiment of the present disclosure.

[0122] Reference signs:

[0123] 100: pre-magnetization assembly; 110: pre-magnetization pipeline; 120: pre-magnetization magnet; 121: first pre-magnetization magnet; 122: second pre-magnetization magnet; 123: pre-magnetization coil; 200: magnet assembly; 210: first magnet; 220: second magnet; 300: flow channel assembly; 310: microfluidic chip; 311: droplet flow channel; 312: sheath liquid inflow channel; 3121: sheath liquid injection port; 313: sample liquid inflow channel; 3131: sample liquid injection port; 314: first liquid outflow channel; 3141: first liquid outflow port; 315: second liquid outflow channel; 3151: second liquid outflow port; 316: positive electrode flow channel; 317: negative electrode flow channel; 320: support frame; 322: first side plate; 323: second side plate; 410: first laser light source; 420: second laser light source; 430: coaxial system; 500: fluorescence detection assembly; 510: first photomultiplier tube; 520: second photomultiplier tube; 610: high-speed camera; 620: light source assembly; 710: bearing plate; 720: fixing assembly; 721: first clamping member; 722: second clamping member; 80: electrode unit; 810: positive electrode; 820: negative electrode; 831: positive electrode connecting member; 832: negative electrode connecting member; 840: electrode mounting plate; 850: first air pump; 860: second air pump; 870: first shield electrode; 880: second shield electrode; 900: processor; 901: memory; 902: communication interface; 903: bus. DETAILED DESCRIPTION

[0124] In order to enable a more detailed understanding of the features and technical content of the present disclosure, the implementation of the present disclosure is described in detail below with reference to the accompanying drawings, which are only used for reference and do not limit the present disclosure. In the following technical description, in order to facilitate explanation, through multiple details, a sufficient understanding of the disclosed embodiments is provided. However, one or more embodiments can still be implemented without these details. In other cases, in order to simplify the drawings, well-known structures and devices can be simplified.

[0125] The terms "first", "second", and the like in the specification and claims of the present disclosure and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0126] In the embodiments of the present disclosure, the terms "upper", "lower", "inner", "middle", "outer", "front", "back" and the like indicate the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the embodiments of the present disclosure and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to indicating the orientation or positional relationship, the above-mentioned part of the terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0127] In addition, the terms "set", "connected", "fixed" should be broadly understood. For example, "connected" can be fixedly connected, detachably connected, or integrally configured; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0128] Unless otherwise specified, the term "a plurality of" means two or more.

[0129] In the embodiments of the present disclosure, the character " / " represents an "or" relationship between the objects before and after it. For example, A / B means A or B.

[0130] The term "and / or" is a description of the association between objects, which means that there can be three relationships. For example, A and / or B means: A or B, or, A and B, three relationships.

[0131] It should be noted that the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0132] Antibodies are one of the important humoral immune mechanisms of the body to resist the invasion of viruses, bacteria and other pathogens. Protective vaccines are an important weapon to curb the spread of various pathogens, which can not only specifically recognize pathogens, but also closely combine with antigens, thereby effectively blocking the damage of pathogens to cells, tissues and organisms. Antibodies are produced by B cells, and are screened layer by layer through the lymphatic system. Only a small number of B cells with gene rearrangement produce high-affinity antibodies. How to effectively separate and enrich B cells secreting high-affinity antibodies is a difficulty in the field of antibody research.

[0133] Binding Figures 1 to 8As shown, the embodiment of the present disclosure provides a droplet sorting system, which comprises a flow channel assembly 300, a fluorescence signal detection device and a sorting device. The flow channel assembly 300 defines a droplet flow channel 311 for the flow of droplets, a first outlet flow channel 314 and a second outlet flow channel 315. The fluorescence signal enhancement device is used to generate a pre-magnetization magnetic field and a first magnetic field. The magnetic particles in the droplets are magnetized and agglomerated in the pre-magnetization magnetic field, and the agglomerated magnetic particles are pulled into a linear shape in the first magnetic field. The fluorescence signal detection device is used to excite the droplets to emit fluorescence and mark the droplets meeting the fluorescence condition as target droplets. The sorting device is arranged corresponding to the outlet section of the droplet flow channel 311. The target droplets flowing through the outlet section of the droplet flow channel 311 enter the first outlet flow channel 314 under the deflection of the sorting device, and the non-target droplets enter the second outlet flow channel 315.

[0134] Exemplarily, the droplet sorting system provided by the embodiment of the present disclosure can be used for sorting biological samples such as cells, bacteria and viruses. At least one cell, bacteria or virus and a fluorescently identifiable marker are included in the droplet.

[0135] Taking one of the use scenarios as an example, the droplet sorting system provided by the embodiment of the present disclosure is used for sorting cells prepared into water-in-oil droplets. At least one cell, a plurality of magnetic particles, a plurality of antibodies specifically combined with the magnetic particles, a plurality of antigens specifically combined with the antibodies and / or secondary antibodies are included in the droplet. At least one of the antigens and / or secondary antibodies is fluorescently dyed.

[0136] The sample liquid sorted by the droplet sorting system includes a plurality of droplets, each of which contains at least one cell, a plurality of magnetic particles, a plurality of fluorescently labeled antigens and fluorescently labeled secondary antibodies. The cell produces a plurality of antibodies after the antigen is recognized, and the antigen can be combined with a plurality of antibodies. The surface of the magnetic particle has a plurality of functional groups, which can be combined with a plurality of antibodies secreted by the cell. The secondary antibody is only combined with a specific antibody. If the target particle group in which the antigen, the antibody, the magnetic particle and the secondary antibody are combined together appears in the droplet, it is considered that the cell in the droplet is a target cell that can produce high-affinity antibodies, and the droplet is a target droplet.

[0137] In order to confirm whether the target particle group exists in the droplet, the antigen and the antibody in the target particle group can be fluorescently identified. Exemplarily, the first laser and / or the second laser can be applied to the droplet. The fluorescent substance in the antigen can emit first fluorescence under the excitation of the first laser, and the fluorescent substance in the secondary antibody can emit second fluorescence under the excitation of the second laser. If the intensity or characteristic peak of the first fluorescence and / or the second fluorescence meets the preset condition, the droplet is considered to be a target droplet.

[0138] The flow channel assembly is used to define a droplet flow channel 311 for the flow of droplets, a first outlet flow channel 314 and a second outlet flow channel 315. The inlet ends of the first outlet flow channel 314 and the second outlet flow channel 315 are communicated with the outlet end of the droplet flow channel 311. The fluorescent signal recognition of the droplets is completed in the droplet flow channel 311, and the target droplets are discharged from the first outlet flow channel 314 after recognition, and the non-target droplets are discharged from the second outlet flow channel 315.

[0139] The sorting device provided by the embodiments of the present disclosure is located outside the droplet flow channel, and the deflection force is applied to the droplets in a non-contact manner during the flow of the droplets. Exemplarily, the sorting device is one or more of a sorting electromagnet, a gas pump or a plurality of electrodes. The target droplets can be accurately recognized by the fluorescent signal detection device, and the target droplets are deflected to the first outlet flow channel by the sorting device after being recognized. The sorting of the droplets does not need to be performed by setting a moving component on the path of the flow of the droplets, so that the droplets are not in contact with the moving component and the cells in the droplets when the droplets are deflected, thereby reducing or avoiding the cells in the droplets being squeezed by the moving component.

[0140] Optionally, the sorting device comprises a sorting electromagnet, the sorting electromagnet is arranged at the outlet section of the droplet flow channel 311, and the sorting electromagnet is started when the target droplets flow through the outlet section of the droplet flow channel 311 to make the target droplets deflect to the first outlet flow channel 314 under the action of the magnetic field force.

[0141] The sorting electromagnet corresponds to the outlet section of the droplet flow channel 311 and is located on the side where the first outlet flow channel 314 is located. When the target droplets flow through the outlet section of the droplet flow channel 311, the sorting electromagnet is energized. After the sorting electromagnet is energized, the magnetic particles in the droplets are subjected to a traction effect, so that the target droplets deflect to the first outlet flow channel 314. By adopting such a setting form, the sorting of the target droplets can be conveniently realized. It should be noted that when the non-target droplets flow through the outlet section of the droplet flow channel 311, the sorting electromagnet is not energized, and the non-target droplets flow to the second outlet flow channel 315 under the action of inertia.

[0142] The droplet sorting system drives the controlled movement of the droplets by magnetic force, the path of the flow of the droplets is not provided with a magnetic moving component, and the droplets are not adhered to the magnetic component when flowing; the sorting of the droplets does not need to be performed by setting a moving component on the path of the flow of the droplets, thereby reducing or avoiding the cells, bacteria and viruses and other samples in the droplets being squeezed by the moving component.

[0143] Optionally, the sorting device further comprises a sorting electromagnet, the sorting electromagnet is arranged at the outlet section of the droplet flow channel 311, and the sorting electromagnet is started when the non-target droplets flow through the outlet section of the droplet flow channel 311 to make the non-target droplets deflect to the second outlet flow channel 315 under the action of the magnetic field force.

[0144] In this case, the target droplet flows to the first outlet flow channel 314 under the action of inertia when the sorting electromagnet is not powered on.

[0145] With such a setting, only the non-target droplet flowing through the outlet section of the droplet flow channel will be affected by the magnetic force of the sorting electromagnet, while the target droplet flowing through the outlet section of the droplet flow channel will not be affected by the magnetic force of the sorting electromagnet. The magnetic particles in the target droplet will not be affected by the magnetic force of the sorting electromagnet, which can reduce or avoid the destruction of cells, bacteria, viruses and other samples in the droplet when the magnetic particles move under the action of the magnetic field force.

[0146] Optionally, in combination with Figure 5 As shown in FIG. 8, the sorting device includes a first air pump 850, which is arranged in the first outlet flow channel 314 and is configured to apply positive pressure to the first outlet flow channel 314 when the non-target droplet flows through the outlet section of the droplet flow channel 311.

[0147] When the first air pump 850 is working, it applies positive pressure to the first outlet flow channel 314. In this way, a certain pressure difference is generated between the first outlet flow channel 314 and the second outlet flow channel 315, and the non-target droplet flowing through the outlet section of the droplet flow channel 311 is deflected to the second outlet flow channel 315 under the action of the pressure difference. The air pump has a fast response speed, and can realize high-speed sorting of the droplet. In addition, when the air pump applies positive pressure to the first outlet flow channel 314, the droplet is uniformly stressed, and the sample in the droplet is not easily damaged.

[0148] It should be noted that the shape of the flow channel can be designed so that the target droplet and the non-target droplet enter the first outlet flow channel 314 when the first air pump 850 is not working. In this way, only by starting and stopping the first air pump 850 can the target droplet enter the first outlet flow channel 314 and the non-target droplet enter the second outlet flow channel 315. The shape of the flow channel is exemplarily that the inlet section of the first outlet flow channel 314 is located on the extension line of the outlet section of the droplet flow channel 311, and the inlet section of the second outlet flow channel 315 forms an angle of less than or equal to 150° with the outlet end of the droplet flow channel 311.

[0149] Using the droplet sorting system provided by the embodiments of the present disclosure, the droplet is driven to move under control by the pressure difference generated by the first air pump, and the path of the droplet flow is not provided with a magnetic component, so that the droplet flow will not be adhered to the magnetic component; The sorting of the droplet does not need to be performed by setting a moving component on the path of the droplet flow, which reduces or avoids the sample in the droplet being broken by the moving component.

[0150] Optionally, in combination with Figure 5As shown, the sorting device includes a second air pump 860, which is arranged in the second liquid outlet channel 315 and configured to apply positive pressure to the second liquid outlet channel 315 when the target liquid droplet flows through the sorting device.

[0151] When the second air pump 860 is working, positive pressure is applied to the second liquid outlet channel 315. Thus, a pressure difference is generated between the first liquid outlet channel 314 and the second liquid outlet channel 315. When the target liquid droplet flows through the outlet section of the liquid droplet channel 311, it is deflected to the first liquid outlet channel 314 under the action of the pressure difference. Thus, high-speed sorting of liquid droplets can be achieved, and the target liquid droplet is less likely to be damaged when deflected.

[0152] It should be noted that the shape of the channel can be designed such that the target liquid droplet and the non-target liquid droplet enter the second liquid outlet channel 315 when the second air pump 860 is not working. Thus, by starting and stopping the second air pump 860, the target liquid droplet can be made to enter the first liquid outlet channel 314 and the non-target liquid droplet can be made to enter the second liquid outlet channel. The shape of the channel is exemplarily such that the inlet section of the second liquid outlet channel 315 is located on the extension line of the outlet section of the liquid droplet channel 311, and the inlet section of the first liquid outlet channel 314 forms an angle of less than or equal to 150° with the outlet end of the liquid droplet channel 311.

[0153] In addition, the sorting device can be provided with both the first air pump 850 and the second air pump 860. In the case where the sorting device includes the first air pump 850 and the second air pump 860, the target liquid droplet enters the first liquid outlet channel 314 under the action of the pressure difference, and the non-target liquid droplet enters the second liquid outlet channel 315 under the action of the pressure difference. Thus, sorting of liquid droplets can be better achieved.

[0154] Optionally, in combination with Figure 8 As shown, the sorting device includes a positive electrode 810 and a negative electrode 820, which are arranged on the same side of the liquid droplet channel. When the positive electrode 810 and the negative electrode 820 are energized, an electric field is formed acting on the outlet section of the liquid droplet channel 311, and the target liquid droplet is deflected to the first liquid outlet channel 314 under the action of the electrophoretic force.

[0155] The length direction of the liquid droplet channel is the flow direction of the liquid droplet, which is taken as the axial direction of the liquid droplet channel. Taking the length direction of the liquid droplet channel as the division line, the liquid droplet channel divides the plane into two regions, one region being a first side and the other region being a second side. The first liquid outlet channel is located in the first region, and the positive electrode and the negative electrode are also located in the first region. The first liquid outlet channel, the positive electrode and the negative electrode are located on the same side of the liquid droplet channel.

[0156] The liquid droplet flows along the liquid droplet flow channel under the driving of external force, and flows from the liquid inlet end of the liquid droplet flow channel to the liquid outlet end of the liquid droplet flow channel. When the liquid droplet flows to the liquid outlet end of the liquid droplet flow channel, it enters the action range of the electrode assembly. When the electrode assembly is powered on, an electric field is formed, and the liquid droplet deflects to the side close to the positive electrode 810 and the negative electrode 820 under the action of the electric field force. When the liquid droplet continues to flow under the action of external force, it is more likely to enter the first liquid outlet flow channel because it is closer to the side where the first liquid outlet flow channel is located. In this process, it can be considered that the target liquid droplet deflects under the action of electrophoresis force, so as to be able to enter the first liquid outlet flow channel.

[0157] Optionally, in combination with Figure 18 As shown in the figure, the sorting device includes a plurality of positive electrodes 810 and a plurality of negative electrodes 820, the plurality of positive electrodes 810 and the plurality of negative electrodes 820 are arranged alternately, and the plurality of negative electrodes 820 are connected.

[0158] The plurality of positive electrodes and the plurality of negative electrodes are arranged alternately, and an electric field is formed between two adjacent positive electrodes and negative electrodes. For a liquid droplet, the plurality of positive electrodes are powered on in sequence, which can pull the liquid droplet to the side where the positive electrode or the negative electrode is located. By using such a setting form, the plurality of positive electrodes and the plurality of negative electrodes can pull the liquid droplet multiple times to deflect the target liquid droplet to the first liquid outlet flow channel. In this way, it can reduce or avoid that the liquid droplet is pulled to break due to too large electrophoresis force. In addition, the form of pulling by the plurality of positive electrodes and the plurality of negative electrodes can improve the throughput of liquid droplet sorting.

[0159] It should be noted that the positive electrode and the negative electrode can be powered by alternating current, and the alternating electric field between the positive electrode and the negative electrode in the case of connecting alternating current can also generate electrophoresis force to deflect the liquid droplet. In this case, the positive electrode and the negative electrode are only used to distinguish opposite electrodes, and to limit that the positive electrode can only be powered by direct current positive or the negative electrode can only be powered by direct current negative.

[0160] Only controlling the on-off of the plurality of positive electrodes can apply electrophoresis force to the liquid droplet multiple times in sequence to deflect the liquid droplet. The form of connecting the plurality of negative electrodes can reduce the difficulty of setting the negative electrodes.

[0161] Optionally, the sorting device includes a plurality of positive electrodes and two negative electrodes, and the two negative electrodes are located on the two sides of the plurality of positive electrodes.

[0162] Any one of the plurality of positive electrodes forms an electric field between the two negative electrodes when powered on, and in the case that the distance between the positive electrode and the two negative electrodes is different, the target liquid droplet deflects to the first liquid outlet flow channel under the action of electrophoresis force. The form of the plurality of positive electrodes cooperating with the two negative electrodes can reduce the number of negative electrodes and thus reduce the difficulty of arranging the negative electrodes.

[0163] Optionally, the sorting device includes a plurality of positive electrodes 810, and the distance between the plurality of positive electrodes 810 and the liquid droplet flow channel 311 is not completely the same.

[0164] The sorting device includes a plurality of positive electrodes 810, which can form an electric field with a certain gradient. The droplets tend to move in the direction of the electric field gradient in the electric field, so as to be better deflected to the corresponding flow channel.

[0165] Optionally, the plurality of positive electrodes are sequentially activated when the target droplet flows through the liquid outlet section of the droplet flow channel.

[0166] If the droplets are simultaneously subjected to the electrophoretic force of multiple electric fields, the movement of the droplets will be unclear, and the plurality of positive electrodes are sequentially activated, so that the target droplet is deflected by only one electric field in a time period. With such a setting form, the sorting device is conducive to deflecting the target droplet to the first liquid outlet flow channel.

[0167] Optionally, in combination with FIGS. 3 to 5 Figure 14 、 Figure 15 、 Figures 17 to 19 As shown in FIGS. 3 to 5, the sorting device includes an electrode assembly, and the electrode assembly includes at least one electrode unit arranged on one side of the droplet flow channel 311. The electrode unit includes one or more positive electrodes 810 and two negative electrodes 820. The positive electrodes 810 are arranged on the first side of the droplet flow channel 311. The two negative electrodes 820 are arranged on the first side of the droplet flow channel 311 and are respectively located on the two sides of the one or more positive electrodes 810.

[0168] The droplet sorting system has a function of identifying a target droplet, and the electrode assembly is used to drive the target droplet to move to a target side. At the electrode assembly, the surface tension of the droplet is affected by the surface charge when the electrodes are powered on, and the change in the surface tension causes the shape of the droplet to change. When the shape of the droplet changes, the droplet moves in a direction in the droplet flow channel, that is, moves toward the side where the electrode assembly is located. This movement of the droplet under the action of the electric field can also be considered as the movement of the droplet under the action of the electrophoretic force.

[0169] It should be noted that the positive electrode and the negative electrode can be connected to alternating current, and the alternating electric field between the positive electrode and the negative electrode in the case of being connected to the alternating current can also generate the electrophoretic force to deflect the droplet. In this case, the positive electrode and the negative electrode are only used to distinguish opposite electrodes, and are not limited to the positive electrode being able to only pass through direct current positive or the negative electrode being able to only pass through direct current negative.

[0170] Specifically, the sorting device includes a sheath liquid inflow channel 312, a sample liquid inflow channel 313, a droplet flow channel 311, a first liquid outlet flow channel 314, and a second liquid outlet flow channel 315.

[0171] The sheath liquid inflow channel 312 is used to fill the sheath liquid, and the sheath liquid inflow channel is provided with a sheath liquid injection port 3121. The sheath liquid is a liquid medium used to focus the water-in-oil droplets or samples. After the water-in-oil droplets or samples are extruded by the sheath liquid, the water-in-oil droplets or samples form a stable liquid flow environment with the sheath liquid, so that the water-in-oil droplets or samples can pass through the droplet flow channel in a single column and substantially along the central axis of the droplet flow channel. Exemplarily, the sheath liquid is an oil phase. The sample liquid inflow channel 313 is used to fill the sample liquid, and the sample liquid inflow channel is provided with a sample liquid injection port 3131. The sample liquid contains water-in-oil droplets, and the droplets at least include a fluorescently identifiable marker. Exemplarily, the droplet sorting system provided by the embodiments of the present disclosure can be used to sort biological samples such as cells, bacteria, viruses, etc. The droplets at least include a cell, a bacterium or a virus, and a fluorescently identifiable marker.

[0172] Exemplarily, the identification marker includes a plurality of magnetic particles, a plurality of antigen labeled with fluorescent markers, and a secondary antibody labeled with fluorescent markers. After the antigen is identified, the cell produces a plurality of antibodies, and the antigen can be combined with a plurality of antibodies. The surface of the magnetic particle has a plurality of functional groups, which can be combined with a plurality of antibodies secreted by the cell. The secondary antibody is combined with only a specific antibody. If the target particle group in which the antigen, the antibody, the magnetic particle and the secondary antibody are combined together appears in the droplet, it is considered that the cell in the droplet is a target cell that can produce a high-affinity antibody, and the droplet is a target droplet.

[0173] The water-in-oil droplets in the sample liquid are used to isolate adjacent droplets. The water-in-oil droplets are further mixed with the sheath liquid in the sheath liquid inflow channel, so as to flow in the droplet flow channel 311 at a preset flow rate and a preset adjacent distance.

[0174] This is conducive to the identification, observation and sorting of the cells in the droplets by the droplet sorting system.

[0175] In the process of pulling the target droplet to the target side of the droplet flow channel, if the acting force is small and the acting time is short, the target droplet is not easy to be deflected. If the acting force is large, the target droplet is easy to be pulled to break, causing sample damage. The electrode assembly provided by the embodiments of the present disclosure includes at least one electrode unit. The electrode unit includes at least one or more positive electrodes and two negative electrodes located on both sides of the one or more positive electrodes.

[0176] The one or more positive electrodes and the two negative electrodes of the electrode unit form electric fields acting on the target droplet, respectively. When the target droplet flows through the electrode assembly, the target droplet is subjected to uniform and continuous pulling force, and then is deflected to the target side of the droplet flow channel. Since the electric field formed by the positive electrode and the two negative electrodes has a large acting range, the droplets in the target droplet are not easy to be pulled to break. The electric field formed by the electrode unit has a long acting time, and the target droplet is easy to be deflected to the target side.

[0177] When an electrode unit includes one positive electrode, the positive electrode and the two negative electrodes form two electric fields. The two electric fields are located on opposite sides of the positive electrode, making it difficult for electric fields to superimpose or interfere with each other.

[0178] Using the electrode assembly provided in the embodiments of this disclosure, the electrode unit can provide a continuous and uniform pulling force to the target droplet, thereby allowing the droplet to pass through the droplet channel at a higher speed, which can significantly improve the throughput of droplet sorting; by providing a pulling force to the target droplet through multiple electric fields of the electrode unit, the pulling force on the target droplet is relatively gentle, and the droplet is not easily torn apart.

[0179] Optionally, combined Figure 14 , Figure 15 As shown, the electrode unit includes multiple positive electrodes, and two negative electrodes are located on both sides of the multiple positive electrodes.

[0180] When the electrode unit includes multiple positive electrodes, the multiple positive electrodes and the two negative electrodes respectively form multiple electric fields. When the target droplet flows through the electrode assembly, the electrophoretic force it experiences first gradually increases and then gradually decreases, and the target droplet is deflected more fully in the droplet channel.

[0181] Optionally, along the droplet flow direction, the distance between the multiple positive electrodes and the droplet channel gradually increases.

[0182] As the target droplet flows through the electrode unit, it is deflected towards the first side of the droplet channel under the deflection force applied by the electrode assembly. The distance between the target droplet and the multiple positive electrodes gradually decreases, and the electric field force it experiences gradually increases. This gradual increase in the distance between the multiple positive electrodes and the droplet channel ensures that the target droplet experiences a uniform force as it flows through the electrode assembly. Furthermore, this arrangement allows for approximately equal voltages to be applied to the multiple positive electrodes, facilitating voltage control of the multiple positive electrodes.

[0183] Optionally, the voltage of the multiple positive electrodes gradually decreases along the direction of droplet flow.

[0184] This configuration ensures that the force exerted on the target droplet remains essentially constant as it flows through the electrode assembly, thereby reducing the risk of the droplet breaking. Furthermore, by setting the voltage of the multiple positive electrodes to decrease gradually, the multiple positive and negative electrodes of the electrode assembly can be positioned as close as possible to the droplet flow channel, which is beneficial for the placement of multiple positive and negative electrodes.

[0185] Optionally, combined Figure 15 As shown, the electrode assembly includes multiple electrode units 80, which are arranged on the first side of the droplet channel.

[0186] The electrode assembly includes a plurality of electrode units, which can further increase the range of the electric field formed by the electrode assembly. In the case of a certain droplet flow rate, the time of the target droplet flowing in the liquid outlet section of the droplet flow channel is increased, so that the duration of the target droplet subjected to the electric field force of the electrode assembly is increased. This allows the electrode assembly to pass through a lower voltage, thereby reducing the electromagnetic signal interference of the electrode assembly to the droplet sorting system and reducing the risk of electrode breakdown. In the case of a certain voltage of the electrode assembly, the droplets can pass through at a higher flow rate, which can increase the number of sorted droplets per unit time, i.e., improve the sorting throughput of the droplet sorting system.

[0187] Optionally, the distance between the plurality of electrode units and the droplet flow channel gradually increases in the droplet flow direction.

[0188] When the target droplet flows through the electrode units, the target droplet is deflected to the first side of the droplet flow channel under the deflection force of the electrode assembly, the distance between the target droplet and the electrode units gradually decreases, and the electric field force gradually increases. The gradually increasing distance between the plurality of electrode units and the droplet flow channel can make the target droplet subjected to uniform force when flowing through the electrode assembly. In addition, by using such a setting mode, the plurality of electrode units can be supplied with substantially equal voltage, which is conducive to the voltage control of the plurality of electrode units.

[0189] Optionally, the voltage of the positive electrode of the plurality of electrode units gradually decreases in the droplet flow direction.

[0190] This can make the force on the target droplet remain substantially unchanged when the target droplet flows through the electrode assembly, thereby reducing the risk of the droplet being pulled apart. In addition, by setting the voltage of the plurality of positive electrodes to gradually decrease, the plurality of positive electrodes and the plurality of negative electrodes of the electrode assembly can be as close to the droplet flow channel as possible, which is conducive to the arrangement of the plurality of positive electrodes and the plurality of negative electrodes.

[0191] Optionally, in combination with Figure 16 As shown in FIG. 8, two adjacent electrode units 80 share one negative electrode 820.

[0192] The two adjacent electrode units share one negative electrode, which can reduce the number of negative electrodes and thus reduce the cost of the electrode assembly, and can also make the target droplet subjected to continuous and uniform electrophoretic force at the electrode assembly. This can improve the success rate of deflecting the target droplet and improve the throughput of the droplet sorting system.

[0193] Optionally, in combination with Figure 17 , Figure 18 As shown in FIG. 9, the electrode unit includes one positive electrode and two negative electrodes, and the positive electrodes and the negative electrodes of the electrode assembly are arranged alternately.

[0194] In one implementation, each electrode unit includes one positive electrode and two negative electrodes. Two adjacent electrode units share a single negative electrode, and the electrodes of the electrode assembly are arranged in an alternating pattern of positive and negative electrodes. With this arrangement, the multiple electric fields formed by the electrode assembly through the multiple positive and negative electrodes are relatively uniform, and adjacent electric fields are less likely to overlap.

[0195] With this configuration, the electrophoretic force exerted on the droplet by a single positive electrode and the two adjacent negative electrodes is relatively uniform, making the droplet less likely to break when it is driven to move.

[0196] Optionally, combined Figures 17 to 19 As shown, the negative electrode 820 of the electrode assembly is connected, and the positive electrode 810 of the electrode assembly is independently and controlled to conduct.

[0197] An electric field is created between the positive and negative electrodes due to a potential difference. Multiple negative electrodes are connected in series, and an electric field is formed between the positive and negative electrodes by supplying power to the positive electrode. This simplifies the wiring of the multiple negative electrodes. Furthermore, the interconnected negative electrodes have equal potentials, which allows for adjustment of the electric field strength by adjusting the voltage at the positive electrode.

[0198] Multiple positive electrodes are independently and controllably energized, allowing for simultaneous or sequential energization. This configuration enables the electrode assembly to perform various sorting methods.

[0199] Optionally, combined Figure 17 , Figure 19 As shown, the electrode assembly also includes a first shielding electrode 870, which is disposed on the second side of the droplet channel 311 and is opposite to the electrode unit 80.

[0200] A first shielding electrode is provided, and the electromagnetic effect generated by the positive electrode towards the second side of the first flow channel is confined within the first shielding electrode. This reduces electromagnetic interference caused by the electric field between the positive and negative electrodes to the electronic components of the droplet sorting system.

[0201] Optionally, the first shielding electrode 870 is connected to the negative electrode 820 of the electrode unit.

[0202] In this configuration, the negative electrode of the electrode unit is grounded, and the first shielding electrode is also grounded. This simplifies the wiring of the negative electrode and the first shielding electrode of the electrode assembly, thereby reducing the cost of the electrode assembly.

[0203] Optionally, combined Figure 17As shown, the electrode assembly further comprises a second shielding electrode 880, which is arranged on the first side of the droplet flow channel and surrounds the electrode unit.

[0204] With the second shielding electrode, the electromagnetic effect generated by the positive electrode on the first side of the first flow channel is limited within the second shielding electrode. In this way, the electromagnetic interference of the electric field between the positive electrode and the negative electrode on the electronic components of the droplet sorting system can be further reduced.

[0205] Optionally, the second shielding electrode 880 is connected to the negative electrode of the electrode unit.

[0206] In this case, the negative electrode of the electrode unit is a ground electrode, and the second shielding electrode is also a ground electrode. In this way, the wiring of the negative electrode and the second shielding electrode of the electrode assembly can be simplified, thereby reducing the cost of the electrode assembly.

[0207] Optionally, the positive electrode and / or the negative electrode of the electrode unit is connected to the power supply through a high-voltage isolation pulse transformer.

[0208] The high-voltage isolation pulse transformer has high electrical isolation between the primary side and the secondary side, which can ensure the safety of the equipment and personnel; the transformer can transmit pulse signals and has good pulse response characteristics. With such a configuration, the safety of the droplet sorting system can be improved.

[0209] If multiple positive electrodes are energized, the target droplet is subjected to the action of multiple electric fields when passing through the electrode assembly, and the target droplet is easily pulled apart. The control device controls the multiple positive electrodes to be energized one by one, and the target droplet is subjected to the action of only one or two electric fields in the same time period, so that the deflection of the target droplet is easy to control, and the droplet is not easy to be pulled apart.

[0210] Using the sorting device provided by the embodiments of the present disclosure, the electrode assembly of the electrode assembly can provide a continuous and uniform pulling force for the target droplet, thereby allowing the droplet to pass through the droplet flow channel at a higher speed, which can significantly improve the sorting throughput; the multiple positive electrodes of the multiple electrode units or the electrode assembly provide a pulling force for the target droplet, and the pulling force received by the target droplet is relatively soft, and the droplet is not easy to be pulled apart.

[0211] Optionally, in combination with Figure 2 , Figures 5 to 8 , Figures 14 to 19 As shown, the flow channel assembly comprises a microfluidic chip 310, and the microfluidic chip defines a droplet flow channel 311, a first droplet outlet flow channel 314, and a second droplet outlet flow channel 315 inside the microfluidic chip.

[0212] The microfluidic chip can be used to realize high-throughput droplet sorting, thereby improving the efficiency of experimental research. The microfluidic chip has low cost, is convenient to use, is convenient to carry, and can reduce experimental cost. The microfluidic chip technology can also realize nondestructive sorting of droplets, and ensures the activity and integrity of the sample.

[0213] Optionally, in combination with Figures 17 to 19 The microfluidic chip also defines a sheath liquid inflow channel 312 and a sample liquid inflow channel 313. The liquid inflow end of the sample liquid inflow channel 313 is used to fill the liquid droplets subjected to the pre-magnetization magnetic field. The liquid outflow end of the sample liquid inflow channel 313 and the liquid outflow end of the sheath liquid inflow channel 312 are connected to the liquid inflow end of the droplet flow channel 311. The liquid droplets subjected to the pre-magnetization magnetic field are mixed with the sheath liquid of the sheath liquid inflow channel 312 and then enter the droplet flow channel 311.

[0214] The pre-magnetized liquid droplets are water-in-oil droplets wrapped by sheath liquid. However, the water-in-oil droplets are used to isolate the mutual interference of antibodies and antigens between adjacent liquid droplets. After the water-in-oil droplets enter the sample liquid inflow channel 313 of the microfluidic chip 310, the water-in-oil droplets are mixed with the sheath liquid of the sheath liquid inflow channel 312 again, so that the liquid droplets can flow in the droplet flow channel 311 at a preset flow rate and a preset adjacent distance. With such a setting form, it is beneficial to identify, observe and sort the liquid droplets in the microfluidic chip 310.

[0215] Optionally, in combination with Figure 14 , Figure 15 , Figures 17 to 19 As shown in the figure, the microfluidic chip defines a positive electrode flow channel 316 and a negative electrode flow channel 317. The positive electrode flow channel 316 is filled with a conductive medium to form a positive electrode, and the negative electrode flow channel 317 is filled with a conductive medium to form a negative electrode.

[0216] The microfluidic chip can be used to realize high-throughput droplet sorting, thereby improving the efficiency of experimental research. The microfluidic chip has low cost, is convenient to use, is convenient to carry, and can reduce experimental cost. The microfluidic chip technology can also realize nondestructive sorting of droplets, and ensures the activity and integrity of the sample.

[0217] The microfluidic chip also defines a plurality of positive electrode flow channels 316 and a plurality of negative electrode flow channels 317. The positive electrode and the negative electrode of the microfluidic chip are located inside the microfluidic chip, which can better drive the liquid droplets to deflect in the plane of the microfluidic chip. In addition, the positive electrode and the negative electrode are in the form of being embedded in the microfluidic chip, which reduces the risk of electrode short circuit or electric leakage of the droplet sorting system.

[0218] Optionally, the conductive medium is metal. The metal conductive medium is filled into the positive electrode flow channel and / or the negative electrode flow channel in a liquid form.

[0219] Adopt such setting form, reduced the positive electrode and negative electrode's processing forming difficulty, reduced the cost of droplet sorting system.

[0220] Optionally, in combination with Figure 17 As shown in the figure, in the case that the electrode assembly further comprises a first shielding electrode, the microfluidic chip further defines a first shielding electrode flow channel 318, the first shielding electrode flow channel is filled with a conductive medium to form a first shielding electrode, and the negative electrode flow channel is also communicated with the first shielding electrode flow channel.

[0221] In this way, the first shielding electrode can be integrally arranged on the microfluidic chip, thereby simplifying the structure of the sorting device and reducing the cost of the sorting device.

[0222] Optionally, in combination with Figure 17 As shown in the figure, in the case that the electrode assembly further comprises a second shielding electrode, the microfluidic chip further defines a second shielding electrode flow channel 319, the second shielding electrode flow channel is filled with a conductive medium to form a second shielding electrode, and the negative electrode flow channel is also communicated with the second shielding electrode flow channel.

[0223] In this way, the second shielding electrode can be integrally arranged on the microfluidic chip, thereby simplifying the structure of the sorting device and reducing the cost of the sorting device.

[0224] Optionally, in combination with Figure 19 As shown in the figure, the microfluidic chip further defines a connecting flow channel 3189, the first end of the connecting flow channel 3189 is connected to the first shielding electrode flow channel 318, and the second end of the connecting flow channel is connected to the second shielding electrode flow channel 319. The second shielding electrode flow channel is directly communicated with the negative electrode flow channel, and the first shielding electrode flow channel is communicated with the second shielding electrode flow channel and the negative electrode flow channel through the connecting flow channel.

[0225] In this way, only one electrode connecting piece can be used to connect multiple negative electrodes, first shielding electrodes and second shielding electrodes, thereby simplifying the connection structure of the negative electrodes, the first shielding electrodes and the second shielding electrodes and reducing the cost of the sorting device.

[0226] Optionally, the microfluidic chip further defines a droplet flow channel 311 for liquid droplets to flow, a first liquid outlet flow channel 314 and a second liquid outlet flow channel 315. The electrode assembly is arranged on the first side of the liquid outlet end of the droplet flow channel 311. When the target liquid droplets flow through the liquid outlet section of the droplet flow channel 311, the electrode assembly is activated to deflect the target liquid droplets to the first liquid outlet flow channel 314. When the non-target liquid droplets flow through the liquid outlet section of the droplet flow channel 311, the electrode assembly is not activated, and the non-target liquid droplets enter the second liquid outlet flow channel 315.

[0227] The positive electrode flow channel 316, the negative electrode flow channel 317, the droplet flow channel 311, the first liquid outlet flow channel 314 and the second liquid outlet flow channel 315 are all configured in the microfluidic chip, so that the integration of the microfluidic chip can be improved, and the processing of the sorting device can be facilitated.

[0228] Optionally, in combination with Figure 3 、 Figure 4 As shown in the figure, the flow channel assembly further includes a support frame 320, the support frame 320 includes a bottom plate, a first side plate 322 and a second side plate 323, the first side plate 322 and the second side plate 323 are oppositely arranged; wherein the microfluidic chip is located between the first side plate 322 and the second side plate 323 and is lapped on the upward one side of the bottom plate.

[0229] The support frame 320 is used for fixing the microfluidic chip 310, specifically, the bottom of the microfluidic chip 310 is lapped on the bottom plate of the support frame 320, and the two side ends of the microfluidic chip 310 are respectively clamped on the first side plate 322 and the second side plate 323 of the support frame 320. By adopting such a setting form, the fixation of the microfluidic chip 310 can be facilitated, and the identification and observation of the droplets in the droplet flow channel 311 can be facilitated.

[0230] Optionally, the sorting device further includes an electrode mounting plate 840, a positive electrode connecting piece 831 and a negative electrode connecting piece 832, the electrode mounting plate 840 is fixed to the first side plate 322 and / or the second side plate 323 of the support frame 320; the positive electrode connecting piece 831 is fixed to the electrode mounting plate 840 and extends to the positive electrode flow channel 316 of the microfluidic chip, and the negative electrode connecting piece 832 is fixed to the electrode mounting plate 840 and extends to the negative electrode flow channel 317 of the microfluidic chip. The positive electrode connecting piece 831 is used for electrically connecting the positive electrode to the power supply, and the negative electrode connecting piece is used for electrically connecting the negative electrode to the power supply.

[0231] By adopting such a setting form, the positive electrode and the negative electrode of the electrode assembly can be conveniently connected to or disconnected from the power supply. In addition, the connection by the electrode connecting piece is tight, and the positive electrode and the negative electrode are not prone to failure due to virtual connection.

[0232] Optionally, the fluorescence signal detection device includes a laser assembly and a fluorescence detection assembly 500, wherein the laser assembly is used for emitting laser to the magnetic particles pulled into a linear shape, and the fluorescent markers in the droplets are excited by the laser to emit fluorescence; the fluorescence detection assembly 500 is used for detecting the fluorescence emitted by the fluorescent markers in the droplets.

[0233] The plurality of particle groups composed of magnetic particles in the droplet form a line shape after the droplet flows through the first section of the droplet flow channel 311. At this time, the laser assembly emits excitation laser to the droplet, and the antigen and the secondary antibody in the plurality of particle groups emit fluorescence. The fluorescence intensity of the antigen and the fluorescence intensity of the secondary antibody are detected to determine whether the droplet is a target droplet. With such a setting form, it is beneficial to fluorescence identification of the droplet, and the accuracy of droplet identification can be improved.

[0234] Optionally, the laser assembly includes a first laser light source 410 for emitting laser of a first wavelength, and one of the antigen and the secondary antibody emits fluorescence of the first wavelength when excited by the laser of the first wavelength; and the fluorescence detection assembly 500 includes a first fluorescence detector for detecting fluorescence of the first wavelength.

[0235] The first laser light source 410 and the first fluorescence detector are provided, so that the fluorescence signal of the antigen or the secondary antibody can be detected, and it is beneficial for the droplet sorting system to determine whether the droplet flowing through the droplet flow channel 311 is a target droplet.

[0236] Optionally, the laser assembly further includes a second laser light source 420 for emitting laser of a second wavelength, and the other of the antigen and the secondary antibody emits fluorescence of the second wavelength when excited by the laser of the second wavelength; and the fluorescence detection assembly 500 further includes a second fluorescence detector for detecting fluorescence of the second wavelength.

[0237] Optionally, the bottom plate of the support frame 320 is provided with an observation window, and at least a first portion of the observation window corresponding to the microfluidic chip is of a transparent material; wherein the light emitting direction of the laser assembly is directed towards the observation window; and / or the detection position of the fluorescence detection assembly 500 corresponds to the observation window.

[0238] With such a setting form, it is beneficial for the laser to act on the particle groups in the droplet, and it is beneficial for the fluorescence detection assembly 500 to receive the fluorescence signal of the particle groups.

[0239] The laser assembly emits laser of the first wavelength and laser of the second wavelength to excite the fluorescence signal of the antigen and the secondary antibody. In this way, the accuracy of droplet identification can be further improved.

[0240] Optionally, the fluorescence detection assembly 500 includes a photomultiplier tube.

[0241] The photomultiplier tube can amplify the optical signal and convert it into an electrical signal, thereby reflecting the strength of the fluorescence signal. The fluorescence detection assembly 500 includes a photomultiplier tube, which can improve the accuracy of droplet identification.

[0242] Optionally, the fluorescence detection assembly 500 comprises a first photomultiplier tube 510 and a second photomultiplier tube 520, the first photomultiplier tube 510 is configured to detect the fluorescence signal of the antigen, and the second photomultiplier tube 520 is configured to detect the fluorescence signal of the secondary antibody.

[0243] By detecting two fluorescence signals through the first photomultiplier tube 510 and the second photomultiplier tube 520, interference between the fluorescence signals can be reduced or avoided, and the accuracy of droplet recognition can be improved.

[0244] Optionally, the laser assembly comprises a first laser light source 410 and a second laser light source 420, the first laser light source 410 is configured to excite the fluorescent substance of the antigen, and the second laser light source 420 is configured to excite the fluorescent substance of the secondary antibody.

[0245] Optionally, the light emitted by the laser assembly is directed towards the observation window.

[0246] With such a setting form, the laser assembly can excite the fluorescent substance in the particle group.

[0247] Optionally, the detection position of the fluorescence detection assembly 500 corresponds to the observation window.

[0248] With such a setting form, the fluorescence detection device can detect the fluorescence signal in the droplet.

[0249] Optionally, the laser assembly further comprises a coaxial system 430, the coaxial system 430 is configured to guide the laser of the first wavelength and the laser of the second wavelength to the droplet in the droplet flow channel 311, and the coaxial system 430 is further configured to guide the fluorescence of the first wavelength and the fluorescence of the second wavelength in the droplet flow channel 311 to the first fluorescence detector and the second fluorescence detector.

[0250] The laser assembly comprises an optical path coaxial system 430, and the installation positions of the first laser light source 410 and the second laser light source 420 are not limited, which is beneficial to the miniaturization of the droplet sorting system. The optical axis collimation degree of the optical path coaxial system 430 is high, the transmission loss of the laser is small, and the transmission efficiency of the laser is high.

[0251] Optionally, the droplet sorting system further comprises a fluorescence signal detection device, the fluorescence signal detection device comprises a light source assembly 620 and an imaging assembly, the light emitting direction of the light source assembly 620 is directed towards the droplet in the first magnetic field; the imaging assembly, the imaging position is directed towards the droplet in the first magnetic field.

[0252] By setting the imaging assembly, the image information of the target droplet can be obtained, which facilitates the user to observe and analyze the target droplet. By setting the imaging assembly, the image information of the suspected target droplet can also be obtained, so that the user can adjust the setting parameters of the droplet sorting system through the image of the suspected target droplet, so as to further improve the accuracy of droplet recognition.

[0253] Optionally, the imaging assembly comprises a high-speed camera 610.

[0254] Optionally, the imaging assembly comprises a high-speed camera 610, a lens of the high-speed camera 610 is directed towards the droplet in the first magnetic field, and a shutter of the high-speed camera 610 is synchronized to open with the light source assembly 620.

[0255] The high-speed camera 610 can still obtain a relatively clear droplet image in the case of high-speed droplet flow. The imaging assembly comprises the high-speed camera 610, and the speed of the droplet flow can be increased. With such a configuration, light pollution of the light source assembly 620 can be reduced, and the service life of the light source assembly 620 can be increased.

[0256] In order to confirm whether the target particle group is in the droplet, the antigen and the antibody in the target particle group can be identified by fluorescence. Specifically, the droplet is irradiated with the first laser and / or the second laser, the fluorescent substance in the antigen can emit the first fluorescence under excitation of the first laser, and the fluorescent substance in the secondary antibody can emit the second fluorescence under excitation of the second laser. If the intensity or the characteristic peak of the first fluorescence and / or the second fluorescence meets the preset condition, the droplet is considered to be a target droplet.

[0257] In actual operation, the antigen and the secondary antibody with fluorescent substances are distributed in each droplet. In some cases, even if the secondary antibody of the droplet is not combined with the antibody, the secondary antibody in the uncombined state can be excited by the laser to appear the second fluorescence which interferes with the judgment. In other cases, even if the secondary antibody of the droplet is combined with the antibody, due to the irregular distribution of the target particle group, the characteristic peak of the fluorescence emitted by the fluorescent substance of the antigen and the secondary antibody is not obvious, which also easily leads to misjudgment.

[0258] Before or while the laser excites the fluorescent substance, a magnetic field is applied to the droplet, so that the target particle group can be arranged according to a certain rule. In this way, the misjudgment of the target droplet can be reduced. Specifically, the magnetic particles are paramagnetic magnetic particles. The magnetic particles themselves do not have magnetism, so that the aggregation of the magnetic particles during or before the incubation of the sample liquid can be avoided to affect the combination of the magnetic particles and the antibody. The magnetic particles with paramagnetism are magnetized in the magnetic field and exhibit magnetism, so as to be distributed according to the direction of the magnetic induction lines of the magnetic field. The position of the magnetic particles changes, and the particle group with the magnetic particles as the key component is distributed in the droplet according to a certain rule. The secondary antibody not combined with the antibody is not distributed according to the rule. When the laser is applied to the droplet, the target particle group distributed according to the certain rule emits fluorescence. At this time, if the first fluorescence characteristic peak in the particle group is relatively obvious, it is considered that the identification is effective, and further, if the characteristic peak of the second fluorescence meets the preset condition, the droplet is considered to be a target droplet.

[0259] The magnetic particles that are not magnetized are first magnetized after entering the magnetic field. A magnetic domain is a region inside a ferromagnetic material in which the atomic magnetic moments (i.e. the spin magnetic moments of the electrons) are aligned, forming a local magnetized region. In the absence of an external magnetic field, these magnetic domains are randomly arranged inside the material, resulting in no macroscopic magnetic properties of the material. When an external magnetic field is applied to the ferromagnetic material, the magnetic moments of the magnetic domains tend to align with the external magnetic field, so that the material exhibits magnetic properties. The magnetic domains are rearranged along the direction of the magnetic induction lines in the magnetic field, so that the magnetic particles exhibit magnetic properties macroscopically. If the direction of the magnetic induction lines changes greatly when the liquid droplets flow, the magnetization effect on the magnetic particles is poor. If the direction of the magnetic induction lines changes little when the liquid droplets flow, the initial position of the magnetic particles in the magnetic field is more likely to be the position of the magnetic particles after being magnetized. That is, after entering the magnetic field, the magnetic particles that are not magnetized are not easily distributed according to a certain rule or along a straight line or a curve, affecting the liquid droplet recognition result.

[0260] The liquid droplet sorting system provided by the embodiments of the present disclosure further comprises a fluorescence signal enhancement device. The fluorescence signal enhancement device is configured to enhance the fluorescence signal of the liquid droplets, so that the target liquid droplets are easily recognized by the fluorescence signal detection device in the liquid droplet flow channel 311.

[0261] In this way, the accuracy of fluorescence signal recognition can be improved.

[0262] Optionally, the fluorescence signal enhancement device comprises a magnet assembly 200, and the magnet assembly 200 is configured to generate a first magnetic field, and the magnetic particles in the liquid droplets are pulled into a linear shape in the first magnetic field.

[0263] In this way, the magnetic particles in the liquid droplets can be arranged more regularly, so that the fluorescence signal characteristic peak is obvious, and the liquid droplet sorting system can recognize the target liquid droplets.

[0264] Optionally, in combination with Figures 5 to 8 As shown in the figure, the magnet assembly 200 comprises a first magnet 210 and a second magnet 220, wherein the first magnet 210 is arranged on one side of the liquid droplet flow channel 311, and the second magnet 220 is arranged on the other side of the liquid droplet flow channel 311; and the length direction of the liquid droplet flow channel 311 is along the direction of cutting the magnetic induction lines between the first magnet 210 and the second magnet 220.

[0265] The side of the first magnet 210 facing the second magnet 220 and the side of the second magnet 220 facing the first magnet 210 are opposite magnetic poles. In this way, the magnetic induction lines between the first magnet 210 and the second magnet 220 are straight lines, which is conducive to pulling the magnetic particles magnetized by the pre-magnetization assembly in the liquid droplets into a straight line, thereby enhancing the fluorescence signal to improve the accuracy of liquid droplet recognition.

[0266] Optionally, the magnet assembly 200 comprises a first magnet 210 and a second magnet 220, wherein the first magnet 210 is arranged on the inward side of the first side plate 322, and the second magnet 220 is arranged on the inward side of the second side plate 323.

[0267] The side of the first magnet 210 facing the second magnet 220 and the side of the second magnet 220 facing the first magnet 210 are opposite magnetic poles. In this way, the magnetic lines of force between the first magnet 210 and the second magnet 220 are straight lines, which is conducive to pulling the particle groups comprising multiple components including magnetic particles into a straight line, thereby enhancing the fluorescence signal to improve the accuracy of droplet recognition. The first magnet 210 and the second magnet 220 are respectively fixed to the first side plate 322 and the second side plate 323 of the support frame 320, which is conducive to fixing the magnet assembly 200.

[0268] Optionally, in combination with Figures 5 to 8 As shown, the fluorescence signal enhancement device further comprises a pre-magnetization assembly for generating a pre-magnetization magnetic field, and the magnetic particles in the droplet are aggregated in the pre-magnetization magnetic field, and the aggregated magnetic particles are pulled into a linear shape in the first magnetic field.

[0269] The magnetic particles in the pre-magnetization magnetic field are re-arranged in the direction of the magnetic induction lines of the pre-magnetization magnetic field, thereby exhibiting magnetism in a macroscopic manner. It should be noted that during the magnetization of the magnetic particles and after the magnetization, the magnetic particles are close to each other under the action of the magnetic field force and the Brownian motion of the magnetic particles, and become an aggregated state. The aggregated state can be defined as the magnetic particles in the droplet attracting and approaching each other.

[0270] The first magnetic field is located at the rear stage of the pre-magnetization magnetic field. The pre-magnetized magnetic particles enter the first magnetic field formed by the magnet assembly 200. Since the magnetic particles are in a magnetized state, they are not easily re-magnetized by the first magnetic field, but tend to rotate or move in the first magnetic field to make the magnetic induction lines inside the magnetic particles tend to be in the same direction as the magnetic induction lines of the first magnetic field. In this case, when the magnetic induction lines in the first magnetic field are straight lines, the multiple magnetic particles are distributed along the straight lines, and when the magnetic induction lines in the first magnetic field are curves, the multiple magnetic particles are distributed along the curves. In addition, the multiple magnetic particles entering the first magnetic field are in an aggregated state, and under the action of the magnetic field force of the first magnetic field, the aggregated magnetic particles are distributed along the same or adjacent magnetic induction lines in the first magnetic field. In this way, the distribution of the magnetic particles in the first magnetic field is more regular, which is conducive to reducing the misjudgment caused by irregular distribution of the magnetic particles, thereby improving the accuracy of droplet recognition.

[0271] After the magnetic particles in the droplet are drawn into a thread, the antigen and / or secondary antibody bound to the magnetic particles are identified by the fluorescence signal detection device. The fluorescence signal detection device marks the droplets that meet the criteria as target droplets, and the sorting device deflects the target droplets to the first outlet channel 314 when the target droplets flow through the outlet section of the droplet channel 311.

[0272] Combination Figure 9 As shown, the distribution of unmagnetized magnetic particles and particle clusters is relatively dispersed; combined with Figure 10 As shown, the magnetic particles and particle clusters after pre-magnetization are distributed in an agglomerated state.

[0273] Combination Figure 11 As shown, after the unmagnetized droplets enter the first magnetic field, the particle cluster is pulled into multiple thin lines, combined with... Figure 12 As shown, after the pre-magnetized droplets enter the first magnetic field, the particle cluster is pulled into a thick line.

[0274] Combination Figure 13 As shown, Figure 13 The left peak in the middle represents the fluorescence intensity characteristic peak of the unmagnetized droplet after entering the first magnetic field, while the right peak represents the fluorescence signal characteristic peak of the premagnetized droplet after entering the first magnetic field. It can be seen that the characteristic peaks are more obvious after the premagnetized droplet enters the first magnetic field, which is beneficial for identifying the fluorescence signal of the droplet.

[0275] Using the droplet sorting system provided in this embodiment, by setting the pre-magnetization component 100, the magnetic particles can be magnetized before entering the first magnetic field, thereby forming an aggregated state. After the magnetized and aggregated magnetic particles enter the first magnetic field, they can be pulled into a thread shape, so that the fluorescent material in the particle cluster can be more fully excited by the laser, thereby improving the droplet recognition accuracy.

[0276] The pre-magnetizing magnetic field generated by the pre-magnetizing component 100 can magnetize and agglomerate the magnetic particles in the droplet. After pre-magnetization, the magnetic particles in the droplet are drawn into a linear shape within the first magnetic field of the magnet component 200. These linear magnetic particles emit fluorescence upon excitation by the fluorescence signal detection device, exhibiting a distinct characteristic peak. This configuration facilitates the identification of target droplets by the droplet sorting system.

[0277] Optionally, the magnetic field strength of the pre-magnetizing magnetic field is greater than the magnetic field strength of the first magnetic field.

[0278] A stronger pre-magnetizing magnetic field can increase the speed at which magnetic particles are magnetized. A weaker first magnetic field can reduce or prevent the magnetic particles from being remagnetized in the first magnetic field, which is beneficial for the magnetic particles in the droplet to be drawn into a linear shape in the first magnetic field.

[0279] The pre-magnetization of the magnetic particles in the droplet can be performed in a container or in a pipeline. When performed in a container, the droplet is in a static state. The container containing the droplet is placed in a pre-magnetization magnetic field, and the magnetic particles in the droplet are magnetized. This form facilitates the control of the magnetization of the magnetic particles. When performed in a pipeline, the droplet is in a flowing state. The pipeline through which the droplet flows is placed in a pre-magnetization magnetic field, and the magnetic particles in the droplet are magnetized in the process of flowing. This form facilitates the driving of the droplet flow and is conducive to the entry of the pre-magnetized droplet into the subsequent first magnetic field.

[0280] Optionally, in combination with Figures 5 to 8 As shown in the figure, the pre-magnetization assembly 100 includes a pre-magnetization pipeline 110 and a pre-magnetization magnet 120. The pre-magnetization pipeline 110 defines a pre-magnetization flow channel for the flow of the droplet. The pre-magnetization magnet 120 is used to generate a pre-magnetization magnetic field. At least part of the pre-magnetization flow channel is located in the pre-magnetization magnetic field.

[0281] The pre-magnetization pipeline 110 defines a first flow channel, and the pre-magnetization magnet forms a pre-magnetization magnetic field. At least part of the first flow channel is located in the pre-magnetization magnetic field, and the droplet flows through the part of the first flow channel located in the pre-magnetization magnetic field and is magnetized in the pre-magnetization magnetic field. The pre-magnetization assembly 100 includes the pre-magnetization pipeline 110 and the pre-magnetization magnet, which is conducive to the magnetization and agglomeration of the magnetic particles in the droplet by the fluorescence signal enhancement device. Since the pre-magnetization of the droplet is performed in the pre-magnetization pipeline 110, the droplet can be pre-magnetized in a flowing state. This allows the pre-magnetization of the magnetic particles in the droplet to be continuously performed, thereby improving the continuity of the pre-magnetization of the droplet by the fluorescence signal enhancement device.

[0282] Optionally, the pre-magnetization flow channel is in communication with the droplet flow channel 311, and the droplet flow channel 311 is located at the rear stage of the pre-magnetization flow channel in the direction of the droplet flow.

[0283] After the droplet passes through the pre-magnetization assembly 100, it enters the droplet flow channel 311 and is drawn into a linear shape when flowing through the first section of the droplet flow channel 311. With such a setting form, it is conducive to the fluorescence signal recognition of the droplet and also conducive to the observation and photography of the droplet. With such a setting form, the droplet continuously flows in the pre-magnetization flow channel and the droplet flow channel 311, which can improve the ability of the fluorescence signal enhancement device to work continuously.

[0284] Optionally, the pre-magnetization magnet includes a first pre-magnetization magnet 121 and a second pre-magnetization magnet 122. The first pre-magnetization magnet 121 is arranged on one side of the pre-magnetization pipeline 110, and the second pre-magnetization magnet is arranged on the other side of the pre-magnetization pipeline 110.

[0285] The first pre-magnetization magnet 121 and the second pre-magnetization magnet 122 are oppositely arranged, the N pole of the first pre-magnetization magnet 121 faces the S pole of the second pre-magnetization magnet 122, or the S pole of the first pre-magnetization magnet 121 faces the N pole of the second pre-magnetization magnet 122. The magnetic induction lines in a straight line form are formed between the first pre-magnetization magnet 121 and the second pre-magnetization magnet 122. When the liquid droplet flows through the pre-magnetization magnet, the direction of the magnetic induction lines is basically unchanged, so that the magnetization effect on the magnetic particles can be improved.

[0286] The first pre-magnetization magnet 121 and the second pre-magnetization magnet 122 are oppositely arranged on two sides of the pre-magnetization pipeline 110, and the magnetic force between the first pre-magnetization magnet 121 and the second pre-magnetization magnet 122 acts on the liquid droplet in the pre-magnetization pipeline 110. The strength of the pre-magnetization magnetic field can be changed by changing the distance between the first pre-magnetization magnet and the second pre-magnetization magnet 122. In addition, the pre-magnetization magnet and the pre-magnetization pipeline 110 are arranged in a separate form, which facilitates the user to assemble and maintain the pre-magnetization assembly 100.

[0287] Optionally, the microfluidic chip 310 is also configured with a pre-magnetization flow channel, and the part of the microfluidic chip 310 configured with the pre-magnetization flow channel serves as the pre-magnetization pipeline 110 described above. After the liquid droplet flows through the pre-magnetization flow channel, the liquid droplet enters the sample liquid inflow channel 313.

[0288] With such an arrangement, the integration level of the liquid droplet sorting system can be improved, thereby reducing the cost of the liquid droplet sorting system.

[0289] Optionally, the pre-magnetization magnet includes a first pre-magnetization magnet 121 and a second pre-magnetization magnet 122, and the first pre-magnetization magnet 121 and the second pre-magnetization magnet 122 are arranged on the upper and lower surfaces of the microfluidic chip 310, respectively.

[0290] With such an arrangement, when the liquid droplet flows in the pre-magnetization flow, the flow direction is along the direction of cutting the magnetic induction lines of the pre-magnetization magnet, which is beneficial to the magnetization of the magnetic particles in the liquid droplet. In addition, the distance of the magnetic particles from the first pre-magnetization magnet and the second pre-magnetization magnet 122 does not change too much when the magnetic particles flow with the liquid droplet, so that the damage to the sample caused by the extrusion of the magnetized magnetic particles to the liquid droplet when the magnetized magnetic particles move towards the first pre-magnetization magnet 121 or the second pre-magnetization magnet 122 can be reduced or avoided.

[0291] Optionally, the pre-magnetization magnet includes a pre-magnetization coil 123, the pre-magnetization coil 123 is wound around the pre-magnetization pipeline 110, the axis of the pre-magnetization coil 123 is along the length direction of the pre-magnetization pipeline 110, and the pre-magnetization coil 123 generates a pre-magnetization magnetic field when energized.

[0292] The pre-magnetizing coil 123 is helically wound around the pre-magnetizing pipe 110. When the pre-magnetizing coil 123 is energized, an electromagnet is formed, which is used to generate a pre-magnetizing magnetic field. The axis of the pre-magnetizing coil 123, i.e. the line around which the pre-magnetizing coil 123 is helically wound, is the N pole and the S pole of the pre-magnetizing pipe 110. With such an arrangement, the volume of the pre-magnetizing assembly 100 can be reduced, and the strength of the pre-magnetizing magnetic field can be adjusted by adjusting the current intensity and / or the number of turns of the pre-magnetizing coil 123.

[0293] Optionally, the pre-magnetizing magnet is used to generate a pre-magnetizing magnetic field with a changing direction, and the magnetic particles in the liquid droplet move and agglomerate under the action of the changing magnetic force when the liquid droplet flows through the pre-magnetizing flow channel.

[0294] The magnetic particles in the liquid droplet are not only magnetized in the pre-magnetizing magnetic field, but also rotate and move under the action of the magnetic force, thereby agglomerating. The magnetic particles can be magnetized in a relatively short time, but a relatively long time is required for agglomeration. When the direction of the pre-magnetizing magnetic field changes, the movement of the magnetic particles in the magnetic field is intensified, thereby accelerating the agglomeration of the magnetic particles. With such an arrangement, the agglomeration effect of the magnetic particles in the liquid droplet in the pre-magnetizing magnetic field can be improved.

[0295] Optionally, the pre-magnetizing magnet includes a plurality of magnet pairs, the plurality of magnet pairs are arranged close to the pre-magnetizing flow channel, a magnetic induction line is formed between each magnet pair, and the magnetic induction lines of the plurality of magnet pairs are different in direction to form a pre-magnetizing magnetic field with a changing direction.

[0296] As an implementation form of generating a pre-magnetizing magnetic field with a changing direction, the pre-magnetizing magnet includes a plurality of magnet pairs, each magnet pair includes two magnets with N and S poles arranged opposite to each other. The plurality of magnet pairs are arranged along the length direction of the pre-magnetizing flow channel, and the two magnets of each magnet pair are respectively arranged on the two sides of the pre-magnetizing flow channel. The magnetic induction lines inside the plurality of magnet pairs are different in direction, so the direction of the magnetic force acting on the liquid droplet flowing through the pre-magnetizing flow channel also changes. With such an arrangement, the magnetic particles in the liquid droplet can be agglomerated in the pre-magnetizing magnetic field.

[0297] Optionally, the plurality of magnet pairs are helically distributed.

[0298] The plurality of magnet pairs are distributed in a form similar to the helix of an RNA molecule, so that the magnetic force acting on the liquid droplet flowing through the pre-magnetizing pipe 110 rotates in one direction. In this way, the magnetic particles can be better rotated and moved in the pre-magnetizing magnetic field, thereby agglomerating.

[0299] Optionally, the pre-magnetization magnet comprises an electromagnet, and the pre-magnetization magnetic field with varying direction is formed by adjusting the current intensity and / or the current direction of the electromagnet; or, the pre-magnetization magnet comprises a coil, the coil is wound around the pre-magnetization pipeline 110, and the pre-magnetization magnetic field is generated when the coil is electrified, and the pre-magnetization magnetic field with varying direction is formed by adjusting the current intensity and / or the current direction of the coil.

[0300] When the current direction of the electromagnet is changed, the magnetic field direction of the electromagnet is changed; when the current intensity of the electromagnet is changed, the magnetic field intensity of the electromagnet is changed. The pre-magnetization assembly 100 comprises an electromagnet, and the pre-magnetization assembly 100 can form the pre-magnetization magnetic field with varying direction by changing the current direction and / or the current intensity.

[0301] When the pre-magnetization magnet comprises a pre-magnetization coil 123 wound around the pre-magnetization pipeline 110, the pre-magnetization magnetic field with varying direction can also be formed by changing the current direction and / or the current intensity.

[0302] When the magnetic field intensity and / or the magnetic field direction of the pre-magnetization magnetic field are changed, the magnetic particles in the liquid droplet can be more fully magnetized and agglomerated, which is beneficial to the magnetic particles being pulled into a linear shape in the first magnetic field.

[0303] Optionally, the pre-magnetization flow channel is a flow channel with varying direction, at least part of the flow channel with varying direction is located in the pre-magnetization magnetic field, and the magnetic particles in the liquid droplet are agglomerated when moving in the flow channel with varying direction under the action of the force of the first magnetic field.

[0304] In the case where the magnetic field direction is unchanged, the pre-magnetization flow channel is a flow channel with varying direction. When the liquid droplet flows in the pre-magnetization flow channel, the magnetic particles in the liquid droplet can change the force of the pre-magnetization magnet in the pre-magnetization magnetic field, which can also accelerate the agglomeration of the magnetic particles in the liquid droplet in the pre-magnetization magnetic field.

[0305] It should be noted that in the case where the magnetic field direction and / or the magnetic field intensity are changed, the direction of the pre-magnetization flow channel is also changed, which can further accelerate the movement of the magnetic particles in the liquid droplet in the pre-magnetization magnetic field, so as to agglomerate the magnetic particles in the liquid droplet.

[0306] Optionally, the pre-magnetization flow channel comprises a plurality of bending sections, and the plurality of bending sections are connected in series to form the pre-magnetization flow channel with varying direction.

[0307] As an implementation form of the pre-magnetization flow channel being a flow channel with a change in direction, the pre-magnetization flow channel comprises a plurality of bending sections. The plurality of bending sections are U-shaped or S-shaped, and the plurality of bending sections are connected end to end. With such a setting form, not only can the magnetic particles in the liquid droplet be subjected to the magnetic field force with a change in direction, but also the flow formation of the liquid droplet in the pre-magnetization magnetic field can be increased, thereby strengthening the pre-magnetization effect and the agglomeration effect of the magnetic particles in the liquid droplet by increasing the time length of the liquid droplet staying in the pre-magnetization magnetic field.

[0308] Optionally, the pre-magnetization flow channel is a spiral flow channel.

[0309] In the case where the pre-magnetization flow channel is a spiral flow channel, the liquid droplet is also subjected to a centrifugal force in the pre-magnetization flow channel. When the liquid droplet flows along the spiral flow channel, the antigen, the antibody, the secondary antibody, and the magnetic particles in the liquid droplet have a tendency to move to the outside of the pre-magnetization flow channel under the action of the centrifugal force. This is not only conducive to the specific binding between the antigen, the antibody, the secondary antibody, and the magnetic particles, but also conducive to the agglomeration of the magnetized magnetic particles.

[0310] Optionally, the pre-magnetization pipeline 110 is wound around the pre-magnetization magnet to form a flow channel with a change in direction.

[0311] In the form that the pre-magnetization pipeline 110 is wound around the pre-magnetization magnet, the pre-magnetization magnet can play a role in fixing the pre-magnetization pipeline 110, so that the structural rigidity of the pre-magnetization assembly 100 can be improved. In addition, in the form that the pre-magnetization pipeline 110 is wound around the pre-magnetization magnet, the volume of the pre-magnetization assembly 100 can be reduced.

[0312] In the first aspect, in the case where the pre-magnetization magnet has a limited size, the length of the pre-magnetization pipeline 110 can be increased, so that the time length of the liquid droplet staying in the pre-magnetization magnetic field can be increased. In this way, the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles can be improved. In the second aspect, in the form that the pre-magnetization pipeline 110 is wound around the pre-magnetization magnet, the radial direction of the pre-magnetization pipeline 110 is along the direction of cutting the magnetic induction lines of the pre-magnetization magnet. When the liquid droplet flows in the pre-magnetization pipeline 110, the magnetic induction lines acting on the magnetic particles are along substantially the same direction, so that the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles can be further improved.

[0313] Optionally, the pre-magnetization magnetic field comprises a first part and a second part, the magnetic field direction of the first part remains unchanged, and the magnetic field direction of the second part changes over time.

[0314] The magnetic particles in the liquid droplet are magnetized in the pre-magnetization magnetic field, and the magnetized magnetic particles are agglomerated in the pre-magnetization magnetic field and in the flow process after leaving the pre-magnetization magnetic field. For the agglomeration of the magnetic particles, it is advantageous that the magnetic field direction of the pre-magnetization magnetic field changes; for the magnetization of the magnetic particles, it is advantageous that the magnetic field direction of the pre-magnetization magnetic field remains unchanged.

[0315] Therefore, the pre-magnetizing magnetic field comprises a first part and a second part, the magnetic field direction of the first part keeps unchanged, and the magnetic field direction of the second part changes with time. In this way, the magnetic particles are magnetized in the first part of the pre-magnetizing magnetic field and agglomerate in the second part of the pre-magnetizing magnetic field. Although the magnetic particles are still magnetized in the second part of the pre-magnetizing magnetic field and agglomerate in the first part of the pre-magnetizing magnetic field, the arrangement can separate the pre-magnetization and the agglomeration of the magnetic particles to some extent, thereby improving the magnetization effect and the agglomeration effect of the magnetic particles.

[0316] Optionally, the pre-magnetizing magnet comprises an alternating current electromagnet, and the alternating current electromagnet forms the second part of the pre-magnetizing magnetic field when energized.

[0317] The magnetic field direction of the alternating current electromagnet changes with the change of the current direction, and the magnetic particles can move more in the second part of the pre-magnetizing magnetic field, thereby better agglomerating.

[0318] Optionally, the pre-magnetizing magnet comprises a direct current electromagnet, and the direct current electromagnet forms the first part of the pre-magnetizing magnetic field when energized.

[0319] The magnetic field direction of the direct current electromagnet keeps unchanged, and the magnetic field strength of the first part of the pre-magnetizing magnetic field formed by the direct current electromagnet is easy to adjust.

[0320] Optionally, the pre-magnetizing pipeline 110 is a flexible hose, and the length of the part of the pre-magnetizing flow channel located in the pre-magnetizing magnetic field is adjusted by moving the pre-magnetizing pipeline 110.

[0321] For the pre-magnetization of the magnetic particles, if the pre-magnetization time is short, the magnetization effect is not obvious, and the magnetic particles are not easy to become the ideal agglomeration state. If the pre-magnetization time is long, the magnetic particles agglomerated into a compact state are not easy to be pulled into a linear shape in the first magnetic field. In the case of a certain liquid drop flow rate, the length of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field determines the time length of the liquid drop staying in the pre-magnetization magnetic field. The time length required for pre-magnetization and the magnetic field strength are different for different liquid drops. In the case of a certain magnetic field strength, by adjusting the length of the part of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field, the pre-magnetization time length of the liquid drop in the pre-magnetization magnetic field can be adjusted. With such a setting form, it is convenient for the user to adjust the pre-magnetization degree of the liquid drop as needed. The length of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field is adjustable, so that the pre-magnetization time can be adjusted by adjusting the length of the part of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field, so that the magnetic particles in the liquid drop can achieve the preset pre-magnetization effect. Exemplarily, as one length adjustment mode, the pre-magnetization pipeline 110 is a flexible pipeline, and the length adjustment of the part of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field is realized by changing the number of turns of the pre-magnetization pipeline 110 in the pre-magnetization magnetic field.

[0322] Optionally, at least part of the pre-magnetization pipeline 110 is spirally arranged in the pre-magnetization magnetic field.

[0323] With such a setting form, in the first aspect, the length of the pre-magnetization pipeline 110 can be increased, thereby increasing the time for the liquid drop to stay in the pre-magnetization magnetic field, and further improving the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles. It should be noted that in the initial stage of the magnetic particles entering the pre-magnetization magnetic field, the N pole and the S pole are present macroscopically. In the subsequent movement process of the liquid drop, the magnetic particles can make the magnetic induction lines in the magnetic particles consistent with the magnetic induction lines of the pre-magnetization magnetic field under the action of the magnetic field force, that is, the magnetic particles adapt to the change of the direction of the magnetic induction lines of the pre-magnetization magnetic field through the rotation of the magnetic particles themselves. Although the spiral form of the pre-magnetization pipeline 110 causes the radial magnetic induction lines of the pre-magnetization pipeline 110 to change multiple times, increasing the time for the magnetic particles to stay in the pre-magnetization magnetic field can improve the pre-magnetization effect on the magnetic particles as a whole.

[0324] Optionally, the liquid drop sorting system further comprises a bearing plate 710 and a fixing assembly 720, wherein the bearing plate 710 is provided with a mounting window; and the fixing assembly 720 is used for fixing the flow channel assembly 300 to the mounting window.

[0325] The flow channel assembly 300 is fixed to the mounting window, and the liquid drop flow channel 311 of the microfluidic chip 310 on the downward side and the upward side is in an exposed state, which is conducive to the fluorescence identification and observation of the liquid drop in the liquid drop flow channel 311.

[0326] Optionally, the light source assembly 620 is arranged below the carrier plate 710.

[0327] With such an arrangement, the light source assembly 620 can be less affected by ambient light. In addition, the carrier plate 710 can serve as a protective plate for the light source assembly 620, preventing the light source assembly 620 from being displaced or damaged during use of the droplet sorting system.

[0328] Optionally, the fluorescence recognition assembly is arranged below the carrier plate 710.

[0329] Similarly, this can reduce the impact of ambient light on the fluorescence recognition assembly, and in addition, the carrier plate 710 simultaneously serves as a protective plate for the fluorescence recognition assembly, preventing the fluorescence recognition assembly from being displaced or damaged during use of the droplet sorting system.

[0330] Optionally, the high-speed camera 610 is arranged below the carrier plate 710.

[0331] This can reduce the impact of ambient light on the high-speed camera 610, and in addition, the carrier plate 710 simultaneously serves as a protective plate for the high-speed camera 610, preventing the high-speed camera 610 from being displaced or damaged during use of the droplet sorting system.

[0332] Optionally, the fixing assembly 720 includes a first clamping member 721 and a second clamping member 722, wherein the first clamping member 721 is configured to fix the first end of the flow channel assembly 300, and the second clamping member 722 is configured to fix the second end of the flow channel assembly 300.

[0333] By clamping the two ends of the flow channel assembly 300 with the first clamping member 721 and the second clamping member 722, the flow channel assembly 300 can be better fixed to the carrier plate 710.

[0334] Optionally, the pre-magnetization assembly 100 is fixed to the carrier plate 710.

[0335] With such an arrangement, not only is the installation of the pre-magnetization assembly 100 facilitated, but it is also beneficial for the user to adjust the length of the pre-magnetization pipeline 110 in the pre-magnetization magnetic field.

[0336] Optionally, the bottom plate of the support frame 320 is provided with an observation window, at least a first portion of the observation window corresponding to the microfluidic chip is made of transparent material, and the imaging position of the imaging assembly faces the first portion of the observation window.

[0337] This is beneficial for the imaging device to obtain droplet images, and can reduce or avoid the imaging device from blocking the microfluidic chip.

[0338] Optionally, the fluorescence recognition assembly is arranged below the carrier plate 710.

[0339] In this way, the influence of ambient light on the fluorescent recognition assembly can be reduced, and the carrier plate 710 can simultaneously serve as a protective plate for the fluorescent recognition assembly, thereby preventing the fluorescent recognition assembly from being displaced or damaged during use of the droplet sorting system.

[0340] Optionally, the upper surface of the microfluidic chip corresponding to the second portion of the observation window is transparent, and the light source assembly 620 emits light towards the second portion of the microfluidic chip.

[0341] The microfluidic chip can be entirely transparent, which facilitates fluorescent signal recognition of the droplets in the droplet flow channel 311 and image acquisition of the droplets. Alternatively, the microfluidic chip can be partially transparent, and at least the portion corresponding to the observation window is transparent. In this way, imaging by the imaging device and visual observation of the droplets in the droplet flow channel 311 by the user are facilitated.

[0342] In combination with Figure 23 As shown in the accompanying drawings, the disclosure provides a droplet sorting method, which includes the following steps.

[0343] S31, the droplet sorting system applies laser to the droplets to cause the fluorescent markers combined with the magnetic particles in the droplets to emit light.

[0344] S41, the droplet sorting system marks the droplets meeting the fluorescent condition as target droplets.

[0345] S51, the droplet sorting system applies a deflection force to the target droplets to deflect the droplets to the target droplet flow channel.

[0346] Illustratively, the droplet sorting method is used to sort cells prepared as water-in-oil droplets, and the droplets include at least one cell, a plurality of magnetic particles, a plurality of antibodies specifically combined with the magnetic particles, a plurality of antigens specifically combined with the antibodies, and / or secondary antibodies, and at least one of the antigens and / or secondary antibodies is fluorescently dyed.

[0347] The number of antigens and / or secondary antibodies combined with the magnetic particles is obtained by fluorescent signal detection, thereby indirectly obtaining the number of specific antibodies produced by the cells. If the number of specific antibodies produced by the cells is large, the cells are target cells, and the droplets containing the cells are target droplets.

[0348] When the target droplets flow, the deflection force applied to the target droplets can cause the target droplets to deviate from the original flow state and move to the target position. In this way, sorting and enrichment of target cells can be achieved.

[0349] Optionally, in combination with Figure 20 As shown in the accompanying drawings, S51, the droplet sorting system applies a deflection force to the target droplets to deflect the droplets to the target droplet flow channel, which includes the following steps.

[0350] S100, the droplet sorting system acquires the flow rate of the target droplet.

[0351] S200, the droplet sorting system determines the first time when the target droplet flows through the working area of the electrode assembly according to the flow rate of the target droplet.

[0352] S300, the droplet sorting system controls the plurality of positive electrodes of the electrode assembly to be sequentially powered on from the first time.

[0353] The sheath liquid inflow channel 312 is used to fill the sheath liquid, and the sheath liquid inflow channel is provided with a sheath liquid injection inlet 3121. The sample liquid inflow channel 313 is used to fill the sample liquid, and the sample liquid injection inlet 3131 is provided on the sample liquid inflow channel. The sample liquid contains water-in-oil droplets, and the droplets at least include a sample such as a cell, a bacterium, a virus, and a plurality of recognition markers.

[0354] When sorting droplets, the sheath liquid is injected from the sheath liquid injection inlet 3121, and the sample liquid is injected from the sample liquid injection inlet 3131. The sheath liquid enters the droplet flow channel 311 along the sheath liquid inflow channel 312, the sample liquid enters the droplet flow channel 311 along the sample liquid inflow channel 313, and the sheath liquid and the sample liquid are mixed in the liquid inlet section of the droplet flow channel 311, so that the droplets in the sample liquid can continue to flow along the droplet flow channel 311 at a certain distance and a certain speed.

[0355] When the droplets flow along the droplet flow channel 311, the sorting device identifies the target droplet, and the droplet sorting system acquires the flow rate of the target droplet. Illustratively, the sorting device includes a fluorescence signal detection device, which detects the fluorescence signal of the droplet and identifies the target droplet and the non-target droplet through the characteristics of the fluorescence signal.

[0356] In the case of uniform flow of the droplets or determination of the flow rate of the droplets, the droplet sorting system determines the first time when the target droplet of the droplets flows through the working area of the electrode assembly. Illustratively, if the flow rate of the droplets is v, the distance of the droplets from being identified to flowing in the droplet flow along the electrode assembly is s1, and the time required for the droplets to flow from the current position to the electrode assembly is t1, then:

[0357] t1=s1 / v1;

[0358] The current time is delayed by t, and the first time when the target droplet flows through the working area of the electrode assembly is obtained.

[0359] The positive electrodes and the negative electrodes of the electrode assembly are located on the same side of the droplet flow channel, and the droplet sorting system controls the plurality of positive electrodes of the electrode assembly to be sequentially powered on from the first time. When the positive electrode is powered on, it forms an electric field acting on the target droplet in the target droplet with the adjacent or nearby negative electrode, and applies an electrophoretic force to pull the target droplet to the side where the electrode assembly is located.

[0360] The target droplet is deflected to the side where the electrode assembly is located during the flow, and the deflected target droplet flows to the first liquid outlet channel 314. The non-target droplet flows through the position where the electrode assembly is located without being affected by the electric field force, and enters the second liquid outlet channel 315 under the action of inertia.

[0361] The target droplet entering the first liquid outlet channel 314 flows along the first liquid outlet channel and flows out from the first liquid outlet 3141 to be collected. The non-target droplet entering the second liquid outlet channel 315 flows along the second liquid outlet channel and flows out from the second liquid outlet 3151. In this way, the droplet sorting of the sample liquid is completed.

[0362] The working area of the electrode assembly is the area where the droplet flow channel can be affected by the electric field. When the target droplet flows through the working area of the electrode assembly, if multiple positive electrodes are powered, the target droplet is affected by multiple electric fields when it flows through the electrode assembly, and the target droplet in the target droplet is easily broken. The droplet sorting method provided by the embodiment of the disclosure controls multiple electrodes to be started one by one, and the target droplet is only affected by one or two electric fields in the same time period, and the deflection of the target droplet is easy to control, and the droplet is not easy to be broken. The droplet sorting method provided by the embodiment of the disclosure can provide a continuous and uniform pulling force for the target droplet, thereby allowing the droplet to pass through the droplet flow channel at a higher speed, which can significantly improve the sorting throughput; the multiple positive electrodes of the multiple electrode units or the electrode assembly provide a pulling force for the target droplet, and the pulling force received by the target droplet is relatively soft, and the droplet is not easy to be broken.

[0363] Optionally, in combination with Figure 21 As shown in the figure, in step S100, the droplet sorting system acquires the flow rate of the target droplet, including:

[0364] S111, the droplet sorting system determines the first time length required for the droplet to flow through the fluorescence signal detection device according to the wave width of the fluorescence signal.

[0365] S112, the droplet sorting system determines the flow rate of the droplet according to the first time length and the working length of the fluorescence signal detection device.

[0366] For accurate sorting of droplets, accurate judgment of the time when the target droplet flows through the sorting device is needed. In combination with Figure 13As shown, the horizontal coordinate is time, and the vertical coordinate is the intensity of the fluorescence signal. When the target droplet flows through the fluorescence signal detection device, the intensity of the fluorescence signal first increases and then decreases with time, which is reflected in the intensity-time graph of the fluorescence signal as a peak. In the case where the sample size in the droplet is relatively uniform and the position of the fluorescence signal detection device is unchanged, the moving distance of the droplet corresponding to the peak (i.e., the working length of the fluorescence signal detection device) is constant. Exemplarily, if the working length of the fluorescence signal detection device is s2, and the width of the peak is t2, then

[0367] V = s2 / t2

[0368] In this way, the flow rate of the droplet can be accurately determined according to the width of the peak of the fluorescence signal and the working length of the fluorescence signal detection device. In addition, the fluorescence signal detection device is used to identify the target droplet and determine the flow rate of the target droplet at the same time, which can reduce the volume of the sorting device and reduce the cost of the sorting device.

[0369] In addition, the fluorescence signal wave width is used to determine the first time length, which is sensitive and fast in detection, and allows the droplet to flow through the fluorescence signal detection device at a higher speed. In this way, the throughput of the sorted droplets can be improved.

[0370] Optionally, in combination with Figure 22 As shown, the droplet sorting system acquires the flow rate of the target droplet in step S100, including:

[0371] S121, the droplet sorting system controls the high-speed camera to continuously capture droplet images at an interval of a second time length.

[0372] S122, the droplet sorting system compares the continuously captured droplet images to determine the displacement distance of the droplet.

[0373] S123, the droplet sorting system determines the flow rate of the droplet according to the displacement distance of the droplet and the second time length.

[0374] The ratio of the displacement distance determined by the comparison unit to the second time length can accurately reflect the flow rate of the droplet. In the case where the droplet image needs to be recorded by the high-speed camera, such a method is low in cost and accurate in result. In addition, the high-speed camera is used to photograph and record the target droplet and determine the flow rate of the target droplet at the same time, which can reduce the volume of the sorting device and reduce the cost of the sorting device.

[0375] By determining the flow rate of the droplet through the droplet image, in the case where the sample size in the droplet is not uniform, the accuracy of the acquired flow rate of the droplet can be improved. Since the droplet flow rate is more accurate, the droplet sorting system can more accurately control the energization of the positive electrode or the individual energization. In this way, the accuracy of the sorted droplets can be improved.

[0376] Optionally, in combination with Figure 21As shown, step S300 includes controlling the plurality of positive electrodes of the electrode assembly to be sequentially powered on from the first time point.

[0377] S311, the droplet sorting system determines the power-on interval of the electrodes according to the flow rate of the target droplet.

[0378] S312, the droplet sorting system controls the plurality of electrodes of the electrode assembly to be sequentially powered on according to the power-on interval from the first time point.

[0379] In the case of sequentially powering on the plurality of electrodes, the distance between adjacent positive electrodes is determined, and the flow rate of the target droplet is adjustable. If the power-on interval of the plurality of electrodes does not match the flow rate of the droplet, the droplet is easily broken or cannot be deflected to the target side. According to the flow rate of the target droplet, the power-on interval of the electrodes is determined, so that the flow rate of the droplet matches the power-on interval, and the efficiency and effect of the electrode assembly in pulling the target droplet to the target side are improved.

[0380] Optionally, in combination with Figure 22 As shown, step S300 includes controlling the plurality of positive electrodes of the electrode assembly to be sequentially powered on from the first time point.

[0381] S321, the droplet sorting system determines the target voltage of the plurality of electrodes according to the flow rate of the target droplet.

[0382] S322, the droplet sorting system controls the plurality of electrodes of the electrode assembly to be sequentially powered on according to the determined power-on voltage from the first time point.

[0383] In the case of a faster target droplet flow rate, the time length of passing through the working area of the electrode assembly is shorter. In order to deflect the target droplet in a shorter time length, the electrode assembly needs a larger voltage to exert a larger electrophoretic force on the target droplet. In the case of a slower target droplet flow rate, the time length of passing through the working area of the electrode assembly is longer. In order to avoid breaking the droplet due to excessive electrophoretic force, the electrode assembly needs a smaller voltage.

[0384] Optionally, in combination with Figure 24 As shown, before step S31, the droplet sorting method further includes:

[0385] S21, the droplet sorting system applies a magnetic field to the droplet to pull the agglomerated magnetic particles into a linear shape.

[0386] In combination with Figure 11 As shown, the particle groups are pulled into multiple thin lines after the non-premagnetized droplet enters the first magnetic field. In this way, the distribution of the magnetic particles in the droplet has a certain directionality, which is beneficial to the accurate identification of the target droplet by the droplet sorting system.

[0387] Optionally, in combination with Figure 24 As shown in FIG. 21, before the droplet sorting system applies a magnetic field to the droplet to pull the agglomerated magnetic particles into a line, the method further comprises:

[0388] S11, the droplet sorting system pre-magnetizes the droplet to agglomerate the magnetic particles in the droplet.

[0389] In combination with Figure 9 As shown in FIG. 22, the distribution of the magnetic particles and particle groups without pre-magnetization is relatively dispersed; in combination with Figure 10 As shown in FIG. 23, the distribution of the magnetic particles and particle groups after pre-magnetization is in an agglomerated state.

[0390] In combination with Figure 12 As shown in FIG. 24, after the pre-magnetized droplet enters the first magnetic field, the particle groups are pulled into a thick line.

[0391] In combination with Figure 13 As shown in FIG. 25, Figure 13 The left peak of the middle in FIG. 25 is the characteristic peak of the fluorescence intensity of the droplet without pre-magnetization after entering the first magnetic field, and the right peak is the characteristic peak of the fluorescence signal of the droplet after pre-magnetization after entering the first magnetic field. It can be seen that the characteristic peak after the pre-magnetized droplet enters the first magnetic field is more obvious, which is conducive to the identification of the fluorescence signal of the droplet.

[0392] In the embodiments of the present disclosure, pre-magnetization of the droplet to agglomerate the magnetic particles in the droplet can be performed by the pre-magnetization component of the fluorescence signal enhancement device in the above embodiments, or can be performed by applying a magnetic field to the droplet after incubation to magnetize and agglomerate the magnetic particles. Since the incubation has been completed, the magnetization of the magnetic particles will not affect the incubation effect.

[0393] In the embodiments of the present disclosure, the application of the magnetic field to the droplet can be completed in the flow channel component described above, or can be completed in other forms of flow sorting devices. The pulling of the particle groups composed of magnetic particles into a line can improve the accuracy of the fluorescence identification of the droplet.

[0394] Using the droplet sorting method provided by the embodiments of the present disclosure, the magnetic particles can be magnetized by the pre-magnetization component before entering the first magnetic field to form an agglomerated state. The magnetized and agglomerated magnetic particles can be better pulled into a line after entering the magnetic field, so that the fluorescent substances in the particle groups can be more fully excited by the laser, thereby improving the identification accuracy of the droplet.

[0395] Optionally, the application of the deflection force to the target droplet to deflect the target droplet to the target flow channel comprises: the droplet sorting system sequentially activates a plurality of electrodes arranged in the flow direction of the droplet to apply electrophoretic force to the target droplet multiple times to deflect the target droplet to the target flow channel.

[0396] The sorting device comprises positive electrodes and negative electrodes, the number of the positive electrodes is multiple, and the multiple positive electrodes are arranged on one side of the droplet flow channel along the direction of the droplet flow channel.

[0397] With such an arrangement, the electrophoretic force acts on the droplet for a longer time, which can better deflect the droplet to the target flow channel.

[0398] Optionally, the target flow channel is connected with a first air pump, and the step of applying a deflection force to the target droplet to deflect the target droplet to the target flow channel comprises: starting the first air pump to apply a positive pressure to the target flow channel to deflect the non-target droplet to the non-target flow channel when the non-target droplet is about to enter the target flow channel.

[0399] The first air pump works to apply a positive pressure to the first droplet outlet flow channel. In this way, a certain pressure difference is generated between the first droplet outlet flow channel and the second droplet outlet flow channel, and the non-target droplet is deflected to the second droplet outlet flow channel under the action of the pressure difference when flowing through the droplet flow channel. The air pump has a fast response speed, and can realize high-speed sorting of the droplet. In addition, when the air pump applies a positive pressure to the first droplet outlet flow channel, the droplet is uniformly stressed, and the droplet in the droplet is not easily damaged.

[0400] Optionally, the target flow channel is connected with a second air pump, and the step of applying a deflection force to the target droplet to deflect the target droplet to the target flow channel comprises: starting the second air pump to apply a positive pressure to the non-target flow channel to deflect the target droplet to the target flow channel when the target droplet is about to enter the non-target flow channel.

[0401] The second air pump works to apply a positive pressure to the second droplet outlet flow channel. In this way, a certain pressure difference is generated between the first droplet outlet flow channel and the second droplet outlet flow channel. The target droplet is deflected to the first droplet outlet flow channel under the action of the pressure difference when flowing through the droplet flow channel. In this way, high-speed sorting of the droplet can also be realized, and the target droplet in the target droplet is not easily damaged when the target droplet is deflected.

[0402] Optionally, the multiple antibodies that specifically bind to the magnetic particles, the multiple antigens that specifically bind to the antibodies, and the multiple secondary antibodies that specifically bind to the antibodies in the droplet are all fluorescently dyed; wherein the droplet sorting system applies laser to the droplet to make the fluorescent markers in the droplet that bind to the magnetic particles emit light, comprising: the droplet sorting system applies first laser and second laser to the linear magnetic particles to make the first fluorescent markers and the second fluorescent markers in the droplet that bind to the magnetic particles emit light; the droplet sorting system labels the droplet that meets the fluorescent condition as a target droplet, comprising: labeling the droplet whose first fluorescent signal meets the first condition and whose second fluorescent signal meets the second condition as a target droplet.

[0403] After the first laser and the second laser are applied to the droplet, the antibody and the antigen in the droplet are excited to emit the first fluorescent signal and the second fluorescent signal. If the intensities of the first fluorescent signal and the second fluorescent signal both satisfy the preset condition, it is considered that the droplet has the particle group in which the magnetic particle, the antibody, the antigen, and the secondary antibody are combined, and the droplet is marked as the target droplet.

[0404] With such a setting form, the accuracy of droplet recognition can be further improved.

[0405] Optionally, the second condition is determined according to the first condition.

[0406] The number of magnetic particles and the number of antigens in different droplets are different. In the case that the number of magnetic particles or the number of antigens in the particle group is small, it is considered that the number of antibodies is small accordingly. Therefore, in the case that the first fluorescent signal is weak, the second condition for the second fluorescent signal is set to be low accordingly, which is beneficial to identify more samples that meet the use purpose.

[0407] Optionally, in combination with Figure 24 As shown in the first fluorescent signal meets the first condition, and the second fluorescent signal meets the second condition, the droplet is marked as the target droplet, the droplet sorting method further includes:

[0408] S61, the droplet sorting system acquires a first time when the target droplet flows through the imaging position.

[0409] S71, the droplet sorting system starts the imaging assembly at the first time to acquire the image of the target droplet.

[0410] With such a setting form, the image of the target droplet can be acquired in the process of sorting the droplet, which is not only beneficial to the user to analyze and research the sample in the target droplet according to the image of the target droplet, but also facilitates the user to adjust the pre-magnetization magnetic field strength, the first magnetic field strength, the droplet flow rate and other parameters of the droplet sorting system according to the acquired image.

[0411] Optionally, in combination with Figure 24 As shown in the first time when the target droplet flows through the imaging position is calculated, the droplet sorting method further includes:

[0412] S81, the droplet sorting system starts the light source assembly to light the imaging assembly at the first time.

[0413] The light source assembly is only started at the first time, which can reduce the light pollution of the light source assembly and improve the service life of the light source assembly.

[0414] In combination with Figure 25 As shown, the embodiment of the present disclosure provides a fluorescent signal detection method for enhancing the fluorescent signal of the droplet, which includes:

[0415] S01, the fluorescent signal detection device pre-magnetizes the droplet to make the magnetic particles in the droplet agglomerate.

[0416] S02, the fluorescent signal detection device applies a magnetic field to the droplet to pull the agglomerated magnetic particles into a linear shape.

[0417] S03, the fluorescent signal detection device applies laser to the droplet to make the fluorescent markers combined with the magnetic particles in the droplet emit light.

[0418] S04, the fluorescent signal detection device detects the fluorescent signal of the fluorescent markers in the droplet.

[0419] Exemplarily, the droplet includes at least one cell, a plurality of magnetic particles, a plurality of antibodies specifically combined with the magnetic particles, a plurality of antigens specifically combined with the antibodies, and / or secondary antibodies, and at least one of the antigens and / or the secondary antibodies is fluorescently dyed.

[0420] In the embodiments of the present disclosure, the pre-magnetization of the droplet to make the magnetic particles in the droplet agglomerate can be performed by the pre-magnetization component of the fluorescent signal enhancement device in the above embodiments, or can be performed by applying a magnetic field to the droplet after the incubation is completed to make the magnetic particles be magnetized and agglomerate. Since the incubation has been completed, the magnetization of the magnetic particles will not affect the incubation effect.

[0421] In the embodiments of the present disclosure, the application of the magnetic field to the droplet can be completed in the flow channel component described above, or can be completed in other forms of flow sorting devices. In any sorting form, the pulling of the particle group with the magnetic particles as the components into a linear shape can improve the accuracy of the fluorescent identification of the droplet.

[0422] The fluorescent signal detection method provided by the embodiments of the present disclosure can be implemented based on the fluorescent signal enhancement device, the fluorescent signal detection device, or the droplet observation device described above.

[0423] After the pre-magnetization of the droplet, the magnetic particles in the droplet are magnetized and agglomerate. The agglomerated magnetic particles are pulled into a linear shape in the first magnetic field. Since the magnetic particles are in a linear shape, the antigens and / or secondary antibodies combined with the magnetic particles are also distributed in a linear shape. After the laser is applied to the magnetic particles in a linear shape, the antigens and / or secondary antibodies can be more fully excited. When the fluorescent signal of the fluorescent markers is detected, the fluorescent signal has a clear characteristic peak. In this way, the antigens and / or secondary antibodies can be more accurately judged to determine whether the droplet contains the target droplet.

[0424] By using the droplet sorting method provided by the embodiments of the present disclosure, the magnetic particles can be magnetized by the pre-magnetization component before entering the first magnetic field to form an agglomerated state. The magnetized and agglomerated magnetic particles can be better pulled into a linear shape after entering the magnetic field, so that the fluorescent substances in the particle group can be more fully excited by the laser, and the identification accuracy of the droplet is improved.

[0425] Optionally, the pre-magnetizing the magnetic particles in the droplet to agglomerate the magnetic particles in the droplet comprises: applying a pre-magnetizing magnetic field to the magnetic particles to magnetize the magnetic particles in the droplet; and changing the direction and / or intensity of the pre-magnetizing magnetic field multiple times to promote the agglomeration of the magnetized magnetic particles in the droplet.

[0426] The magnetic particles in the droplet are not only magnetized in the pre-magnetizing magnetic field, but also rotate and move under the action of magnetic force to agglomerate. The magnetic particles can be magnetized in a short time, but a longer time is needed for agglomeration. When the direction of the pre-magnetizing magnetic field changes, the movement of the magnetic particles in the magnetic field is intensified, thereby accelerating the agglomeration of the magnetic particles. By using such a method, the agglomeration effect of the magnetic particles in the droplet in the pre-magnetizing magnetic field can be improved.

[0427] Optionally, the changing the direction of the pre-magnetizing magnetic field multiple times comprises: controlling the direction of the pre-magnetizing magnetic field to change over time; or changing the angle of the droplet in the pre-magnetizing magnetic field multiple times.

[0428] As an implementation form, the pre-magnetizing magnet comprises an alternating current electromagnet. When the pre-magnetizing magnet is powered on, a circumferential magnetic field is generated. As another implementation form, the droplet forms a flow path with a changing direction when flowing in the pre-magnetizing magnetic field. This is conducive to the movement of the magnetic particles in the droplet in the pre-magnetizing magnetic field and thus the agglomeration of the magnetic particles.

[0429] Optionally, the changing the intensity of the pre-magnetizing magnetic field multiple times comprises: controlling the intensity of the pre-magnetizing magnetic field to change over time; or changing the position of the droplet in the pre-magnetizing magnetic field multiple times.

[0430] As an implementation form, the pre-magnetizing magnet comprises an electromagnet, and the intensity of the pre-magnetizing magnetic field is changed by changing the current intensity of the electromagnet. As another implementation form, the droplet is at different positions in the pre-magnetizing magnetic field when flowing in the pre-magnetizing magnetic field, so that the intensity of the magnetic field acting on the droplet changes. This is conducive to the movement of the magnetic particles in the droplet in the pre-magnetizing magnetic field and thus the agglomeration of the magnetic particles.

[0431] In combination Figure 26 As shown in the accompanying drawings, the embodiments of the present disclosure provide an apparatus for controlling a droplet sorting system, which comprises a processor 900 and a memory 901. Optionally, the apparatus can further comprise a communication interface 902 and a bus 903. The processor, the communication interface, and the memory can communicate with each other through the bus. The communication interface can be used for information transmission. The processor can invoke the logical instructions in the memory to execute the droplet sorting method of the above-mentioned embodiments.

[0432] In addition, the logic instructions in the memory described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium.

[0433] The memory, as a computer readable storage medium, can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiments of the present disclosure. The processor executes the program instructions / modules stored in the memory, thereby performing function applications and data processing, that is, implementing the droplet sorting method in the above embodiments.

[0434] The memory can include a program storage area and a data storage area, wherein the program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory.

[0435] The embodiments of the present disclosure provide a droplet sorting system, comprising: a droplet sorting system body, and the device for controlling the droplet sorting system described above. The device for controlling the droplet sorting system is installed on the product body. The installation relationship described herein is not limited to being placed in the product, but also includes installation connection with other components of the product, including but not limited to physical connection, electrical connection or signal transmission connection, etc. Those skilled in the art can understand that the device for controlling the droplet sorting system can be adapted to the feasible product body, and thus other feasible embodiments can be realized.

[0436] The embodiments of the present disclosure provide a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are configured to execute the droplet sorting method described above.

[0437] The computer readable storage medium described above can be a transitory computer readable storage medium or a non-transitory computer readable storage medium.

[0438] The technical solutions of the embodiments of the present disclosure can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes one or more instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, etc. various media that can store program codes, or a transitory storage medium.

[0439] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0440] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0441] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to apparatuses, devices, etc.) can be implemented in other manners. For example, the described apparatus embodiments are merely schematic. For example, the division of the units is merely a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or among them, can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electric, mechanical, or other forms.

[0442] The flowcharts and block diagrams in the drawings show the possible implementation architectures, functions, and operations of the system, method, and computer program product according to the embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment, or a part of code, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks can occur in an order different from that noted in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the drawings, the operations or steps corresponding to different blocks can also occur in an order different from that disclosed in the descriptions, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. Each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A droplet sorting system, characterized in that, include: A flow channel assembly defines a droplet flow channel, a first liquid outlet channel, and a second liquid outlet channel for droplet flow. The flow channel assembly includes a microfluidic chip, which internally defines the droplet flow channel, the first liquid outlet channel, and the second liquid outlet channel. A fluorescence signal detection device is used to excite droplets to emit fluorescence and mark droplets that meet the fluorescence conditions as target droplets; The sorting device is set up with the liquid outlet section corresponding to the droplet flow channel. The target droplets flowing through the liquid outlet section of the droplet flow channel enter the first liquid outlet channel under the deflection action of the sorting device, while the non-target droplets enter the second liquid outlet channel. A fluorescence signal enhancement device is used to enhance the fluorescence signal of magnetic particles in a droplet. The fluorescence signal enhancement device includes a magnet assembly for generating a first magnetic field in which the magnetic particles in the droplet are drawn into a linear shape. A pre-magnetizing component is used to generate a pre-magnetizing magnetic field. Magnetic particles in the droplet are magnetized and agglomerated in the pre-magnetizing magnetic field. The agglomerated magnetic particles are pulled into a thread shape in a first magnetic field. The magnetic field strength of the pre-magnetizing magnetic field is greater than that of the first magnetic field. The sorting device includes: A sorting electromagnet is installed in the outlet section of the droplet flow channel. The sorting electromagnet is activated when the target droplet flows through the outlet section of the droplet flow channel so that the target droplet is deflected to the first outlet flow channel under the action of magnetic field force. A first air pump is disposed in the first liquid outlet channel, and the first air pump is configured to apply positive pressure to the first liquid outlet channel when a non-target droplet flows through the liquid outlet section of the droplet channel; A second air pump is disposed in the second liquid outlet channel, and the second air pump is configured to apply positive pressure to the second liquid outlet channel when the target droplet flows through the sorting device; The positive electrode is positioned on one side of the droplet flow channel; The negative electrode is disposed on the same side of the droplet channel as the positive electrode. When the positive electrode and the negative electrode are energized, they form an electric field that acts on the liquid outlet section of the droplet channel. Under the action of electrophoretic force, the target droplet is deflected to the first liquid outlet channel. The sorting device includes multiple positive electrodes and multiple negative electrodes, which are alternately arranged and connected to each other. The multiple positive electrodes and multiple negative electrodes pull the droplets multiple times, thereby deflecting the target droplets to the first liquid outlet channel, so as to reduce or avoid the droplets being torn by excessive electrophoretic force.

2. The droplet sorting system according to claim 1, characterized in that, The sorting device includes multiple positive electrodes and two negative electrodes, with the two negative electrodes located on either side of the multiple positive electrodes.

3. The droplet sorting system according to claim 1, characterized in that, The sorting device includes multiple positive electrodes, which are not all at the same distance from the droplet channel, or the multiple positive electrodes are activated sequentially when the target droplet flows through the outlet section of the droplet channel.

4. The droplet sorting system according to claim 1, characterized in that, The sorting device further includes: An electrode assembly includes at least one electrode unit disposed on one side of a droplet flow channel; The electrode unit includes: One or more positive electrodes; Two negative electrodes are located on either side of the one or more positive electrodes.

5. The droplet sorting system according to claim 4, characterized in that, Along the direction of droplet flow, the distance between the multiple positive electrodes and the droplet channel gradually increases; and / or, Along the direction of droplet flow, the voltage of the multiple positive electrodes gradually decreases.

6. The droplet sorting system according to claim 4, characterized in that, The electrode assembly includes multiple electrode units, which are arranged on the first side of the droplet channel.

7. The droplet sorting system according to claim 4, characterized in that, Two adjacent electrode units share a single negative electrode.

8. The droplet sorting system according to claim 1, characterized in that, The positive electrode and / or the negative electrode are connected to a power source via a high-voltage isolation pulse transformer.

9. The droplet sorting system according to claim 1, characterized in that, The microfluidic chip further defines the sheath fluid inflow channel and the sample fluid inflow channel. The inlet end of the sample fluid inflow channel is used to fill droplets that have passed through the pre-magnetized magnetic field. The outlet end of the sample fluid inflow channel and the outlet end of the sheath fluid inflow channel are connected to the inlet end of the droplet channel. After the droplets pass through the pre-magnetized magnetic field and mix with the sheath fluid, they enter the droplet channel.

10. The droplet sorting system according to claim 9, characterized in that, The microfluidic chip further defines a positive electrode channel and a negative electrode channel, wherein the positive electrode channel is filled with a conductive medium to form a positive electrode, and / or the negative electrode channel is filled with a conductive medium to form a negative electrode.

11. The droplet sorting system according to claim 10, characterized in that, The conductive medium is made of metal, and the metal conductive medium is filled into the electrode channel in liquid form.

12. The droplet sorting system according to claim 1, characterized in that, The flow channel assembly also includes: The supporting frame includes a base plate, a first side plate, and a second side plate, with the first side plate and the second side plate arranged opposite to each other; The microfluidic chip is located between the first side plate and the second side plate, and overlaps the upward-facing side of the base plate.

13. The droplet sorting system according to claim 12, characterized in that, The sorting device further includes: An electrode mounting plate is fixed to the first side plate and / or the second side plate of the support frame; A positive electrode connector is fixed to the electrode mounting plate and extends toward the microfluidic chip. The positive electrode connector is used to connect the positive electrode to a power source. A negative electrode connector is fixed to the electrode mounting plate and extends toward the microfluidic chip. The negative electrode connector is used to connect the negative electrode to a power source.

14. The droplet sorting system according to any one of claims 1 to 13, characterized in that, The fluorescence signal detection device includes: A laser component is used to emit a laser beam toward magnetic particles that have been stretched into a wire shape, and fluorescent markers in the droplets are excited by the laser to emit fluorescence. A fluorescence detection component used to detect fluorescence emitted by fluorescent markers in droplets.

15. The droplet sorting system according to claim 14, characterized in that, The laser component includes: A first laser source is used to emit a first wavelength of laser light, and one of the antigen and the secondary antibody emits fluorescence of the first wavelength when excited by the first wavelength of laser light. The fluorescence detection component includes: The first fluorescence detector is used to detect fluorescence at the first wavelength.

16. The droplet sorting system according to claim 15, characterized in that, The laser component also includes: A second laser source is used to emit a second wavelength of laser light, which emits a second wavelength of fluorescence when the other of the antigen and secondary antibody is excited by the second wavelength of laser light. The fluorescence detection component also includes: The second fluorescence detector is used to detect fluorescence at a second wavelength.

17. The droplet sorting system according to claim 16, characterized in that, The laser component also includes: A coaxial system is used to guide a first wavelength laser and a second wavelength laser to a droplet in a droplet channel. The coaxial system is also used to guide the first wavelength fluorescence and the second wavelength fluorescence in the droplet channel to a first fluorescence detector and a second fluorescence detector.

18. The droplet sorting system according to any one of claims 1 to 13, characterized in that, The fluorescence signal detection device includes: The light source assembly emits light towards the droplet in the first magnetic field; The imaging component is positioned so that the imaging point is oriented towards the droplet in the first magnetic field.

19. The droplet sorting system according to claim 18, characterized in that, The imaging component includes: A high-speed camera, with its lens pointed towards the droplet in the first magnetic field, has its shutter opened synchronously with the light source assembly.

20. The droplet sorting system according to any one of claims 1 to 13, characterized in that, The pre-magnetization component includes: The pre-magnetized conduit defines a pre-magnetized flow path for droplet flow; A pre-magnetized magnet is used to generate a pre-magnetized magnetic field, at least a portion of the pre-magnetized flow channel being located within the pre-magnetized magnetic field.

21. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized channel is connected to the droplet channel, and the droplet channel is located after the pre-magnetized channel along the droplet flow direction.

22. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized magnet includes: A first pre-magnetized magnet is disposed on one side of the pre-magnetized pipeline; The second pre-magnetized magnet is disposed on the other side of the pre-magnetized pipeline.

23. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized magnet includes: A pre-magnetizing coil is wound around the pre-magnetizing conduit, the axis of the pre-magnetizing coil is along the length of the pre-magnetizing conduit, and the pre-magnetizing magnetic field is generated when the pre-magnetizing coil is energized.

24. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized magnet is used to generate a pre-magnetized magnetic field with changing direction. When the magnetic particles in the droplet are in the pre-magnetized channel, they move and agglomerate under the action of the changing magnetic field force.

25. The droplet sorting system according to claim 24, characterized in that, The pre-magnetized magnet includes multiple magnet pairs, which are arranged close to the pre-magnetized flow channel. Magnetic field lines are formed between each magnet pair, and the magnetic field lines of the multiple magnet pairs are in different directions to form a pre-magnetized magnetic field with varying directions.

26. The droplet sorting system according to claim 24, characterized in that, The pre-magnetized magnet includes an electromagnet, and the direction of the current in the electromagnet is adjusted to form a pre-magnetized magnetic field with varying direction; or, The pre-magnetized magnet includes a coil wound around the pre-magnetized conduit. When the coil is energized, it generates the pre-magnetized magnetic field. The direction of the pre-magnetized magnetic field can be varied by adjusting the current intensity and / or current direction of the coil.

27. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized channel is a channel with changing direction, and at least a portion of the channel with changing direction is located in the pre-magnetized magnetic field. When the magnetic particles in the droplet move in the channel with changing direction, they are moved and aggregated by the force of the first magnetic field.

28. The droplet sorting system according to claim 27, characterized in that, The pre-magnetized flow channel includes multiple bends, which are connected end to end to form a pre-magnetized flow channel with changing direction.

29. The droplet sorting system according to claim 28, characterized in that, The pre-magnetized flow channel is a spiral flow channel.

30. The droplet sorting system according to claim 29, characterized in that, The pre-magnetized conduit is wound around the pre-magnetized magnet to form the flow channel with the changing direction.

31. The droplet sorting system according to claim 20, characterized in that, The pre-magnetizing magnetic field includes a first part and a second part. The direction of the magnetic field in the first part remains unchanged, while the direction of the magnetic field in the second part changes over time.

32. The droplet sorting system according to claim 31, characterized in that, The pre-magnetized magnet includes an AC electromagnet, which forms the second part of the pre-magnetized magnetic field when energized.

33. The droplet sorting system according to claim 31, characterized in that, The pre-magnetized magnet includes a DC electromagnet, and the DC electromagnet forms the first part of the pre-magnetized magnetic field when energized.

34. The droplet sorting system according to claim 20, characterized in that, The pre-magnetized conduit is a flexible hose, and the length of the portion of the pre-magnetized flow channel located in the pre-magnetized magnetic field can be adjusted by moving the pre-magnetized conduit.

35. A method for sorting droplets, characterized in that, The droplet sorting method is applied to the droplet sorting system according to any one of claims 1 to 34, the method comprising: Applying a laser to a droplet causes a fluorescent marker bound to magnetic particles within the droplet to emit light; The droplets that meet the fluorescence condition are marked as the target droplets; A deflection force is applied to the target droplet to deflect it into the target droplet channel.

36. The droplet sorting method according to claim 35, characterized in that, Before applying a laser to the droplet to cause the fluorescent markers bound to the magnetic particles in the droplet to emit light, the process also includes: A magnetic field is applied to the droplets to pull the aggregated magnetic particles into a thread.

37. The droplet sorting method according to claim 36, characterized in that, Before applying a magnetic field to the droplets to pull the aggregated magnetic particles into a thread, the process also includes: Pre-magnetize the droplets to cause the magnetic particles in the droplets to agglomerate.

38. The droplet sorting method according to claim 35, characterized in that, Applying a deflection force to the target droplet to deflect its tip toward the target flow channel includes: Multiple electrodes positioned along the droplet flow direction are activated sequentially to apply electrophoretic force to the target droplet multiple times, causing the target droplet to deflect to the target flow channel.

39. The droplet sorting method according to claim 35, characterized in that, The target flow channel is connected to a first air pump, which applies a deflection force to the target droplet to deflect the end of the target droplet into the target flow channel, including: If a non-target droplet is about to enter the target flow channel, the first air pump is activated to apply positive pressure to the target flow channel so that the non-target droplet is deflected to the non-target flow channel.

40. The droplet sorting method according to claim 35, characterized in that, A second air pump is connected to the non-target flow channel to apply a deflection force to the target droplet, causing the droplet tip to deflect into the target flow channel, including: When the target droplet is about to enter the non-target flow channel, the second air pump is activated to apply positive pressure to the non-target flow channel so that the target droplet is deflected to the target flow channel.

41. The droplet sorting method according to claim 35, characterized in that, The droplet includes at least one cell, multiple magnetic particles, multiple antibodies that specifically bind to the magnetic particles, and multiple antigens and / or secondary antibodies that specifically bind to the antibodies, all of which are fluorescently stained. The step of applying a laser to a droplet to make the fluorescent markers bound to the magnetic particles in the droplet glow includes: applying a first laser and a second laser to the linear magnetic particles to make the first fluorescent markers and the second fluorescent markers bound to the magnetic particles in the droplet glow; the step of marking droplets that meet the fluorescence conditions as target droplets includes: marking droplets whose first fluorescence signal meets the first condition and whose second fluorescence signal meets the second condition as target droplets.

42. The droplet sorting method according to claim 41, characterized in that, The second condition is determined based on the first condition.

43. The droplet sorting method according to claim 41 or 42, characterized in that, After marking the droplets whose first fluorescence signal meets the first condition and whose second fluorescence signal meets the second condition as target droplets, the method further includes: Acquire the first moment when the target droplet flows through the imaging position; The imaging component is activated at the first moment to obtain an image of the target droplet.

44. The droplet sorting method according to claim 43, characterized in that, After calculating the first moment when the target droplet flows through the imaging position, the method further includes: The light source component is activated immediately to provide supplemental lighting for the imaging component.

Images