Fluorescence signal enhancement device, fluorescence signal detection device, and liquid droplet observation device

Abstract

The utility model relates to the technical field of cell sorting, and discloses a fluorescence signal enhancement device which comprises a pre-magnetization assembly and a magnet assembly, the pre-magnetization assembly is used for generating a pre-magnetization magnetic field, and magnetic particles in liquid drops are magnetized and agglomerated in the pre-magnetization magnetic field; the magnet assembly is used for generating a first magnetic field, and the magnetic particles agglomerated in the liquid drops are pulled into a linear shape in the first magnetic field. The utility model further discloses a fluorescence signal detection device and a liquid drop observation device.

Description

Technical Field

[0001] The present application relates to the field of cell sorting technology, for example, to a fluorescence signal enhancement device, a fluorescence signal detection device, and a droplet observation device. Background Art

[0002] Antibodies are one of the body's key humoral immune mechanisms for defending against invasion by pathogens such as viruses and bacteria. Protective vaccines are a crucial weapon in curbing the spread of various pathogens. They not only specifically identify pathogens but also bind closely to antigens, effectively blocking damage to cells, tissues, and the body. Antibodies are produced by B cells and undergo multiple rounds of screening through the lymphatic system. Only a very small number of B cells undergo gene rearrangement to produce high-affinity antibodies. Effectively isolating and enriching B cells that secrete high-affinity antibodies is a challenge in antibody research.

[0003] A system for detecting, sorting, and dispensing droplets for biological assays is disclosed in the related art. The system includes: a microfluidic device including a first channel connected to a second channel and a waste channel via a first sorting junction; a plurality of water-in-oil droplets, wherein at least two of the plurality of water-in-oil droplets each include at least one cell, at least one particle, or at least one cell and 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 includes 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 including a dispensing nozzle disposed downstream of the second detection point; and a processor configured to index each of the plurality of target droplets dispensed by the dispensing nozzle using a first signal of the same target droplet detected by the first detector or sensor at the first detection point, a second signal of the same target droplet detected by the second detector or sensor at the second detection point, or both the first and second signals.

[0004] During the implementation of the embodiments of the present disclosure, it was found that at least the following problems exist in the related art:

[0005] When a droplet flows through the first or second detection point, a magnet, magnet pair, or magnet array is required to arrange the particles in the droplet according to a certain pattern so that their characteristics become obvious. The magnetic particles in the droplet are magnetized near the monitoring point and arranged by the magnetic field force. The particles in the droplet interact with the closer particles to form a linear shape. When the magnet distribution in the droplet is relatively diffuse, the particles in the droplet are rearranged into multiple thin lines in the magnetic field. When the particles in the droplet are arranged as multiple thin lines, the characteristic peak of the fluorescence signal is not obvious when the droplet is fluorescently identified, which affects the accuracy of cell identification.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Utility Model Content

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a fluorescence signal enhancement device, a fluorescence signal detection device, and a droplet observation device to improve the accuracy of droplet recognition.

[0009] In some embodiments, the fluorescence signal enhancement device includes a pre-magnetization component and a magnet component, wherein the pre-magnetization component is used to generate a pre-magnetization magnetic field, and the magnetic particles in the droplets are magnetized and agglomerated in the pre-magnetization magnetic field; the magnet component is used to generate a first magnetic field, and the agglomerated magnetic particles in the droplets are pulled into a linear shape in the first magnetic field.

[0010] In some embodiments, the pre-magnetization magnetic field has a magnetic field strength greater than a magnetic field strength of the first magnetic field.

[0011] In some embodiments, the pre-magnetization component includes a pre-magnetization pipeline and a pre-magnetization magnet, wherein the pre-magnetization pipeline defines a pre-magnetization flow channel for the flow of droplets; the pre-magnetization magnet is used to generate a pre-magnetization magnetic field, and at least a portion of the pre-magnetization flow channel is located in the pre-magnetization magnetic field.

[0012] In some embodiments, the pre-magnetization magnet includes a pre-magnetization coil, which is wound around the pre-magnetization pipeline. The axis of the pre-magnetization coil is along the length direction of the pre-magnetization pipeline. When the coil is energized, the pre-magnetization magnetic field is generated.

[0013] In some embodiments, the pre-magnetized magnet includes a first pre-magnetized magnet and a second pre-magnetized magnet, wherein the first pre-magnetized magnet is disposed on one side of the pre-magnetized pipeline; and the second pre-magnetized magnet is disposed on the other side of the pre-magnetized pipeline.

[0014] In some embodiments, the pre-magnetized magnet is used to generate a pre-magnetized magnetic field with changing direction, and the magnetic particles in the droplets move and agglomerate under the action of the changing magnetic field force when in the pre-magnetized flow channel.

[0015] In some embodiments, the pre-magnetized magnet includes multiple magnet pairs, and the multiple magnet pairs are arranged near the pre-magnetized flow channel. Magnetic flux lines are formed between each magnet pair, and the directions of the magnetic flux lines of the multiple magnet pairs are different to form the pre-magnetized magnetic field with changing direction.

[0016] In some embodiments, the pre-magnetized magnet includes an electromagnet, and the pre-magnetized magnetic field with changing direction is formed by adjusting the current intensity and / or current direction of the electromagnet; or, the pre-magnetized magnet includes a coil, and the coil is wound around the pre-magnetized pipeline. When the coil is energized, the pre-magnetized magnetic field is generated, and the pre-magnetized magnetic field with changing direction is formed by adjusting the current intensity and / or current direction of the coil.

[0017] In some embodiments, the pre-magnetized flow channel is a direction-changing flow channel, at least a portion of which is located in the pre-magnetized magnetic field. When the magnetic particles in the droplets move in the direction-changing flow channel, they are affected by the force of the first magnetic field and move and agglomerate.

[0018] In some embodiments, the pre-magnetized flow channel includes a plurality of bent segments, and the plurality of bent segments are connected end to end to form a pre-magnetized flow channel with a changing direction.

[0019] In some embodiments, the pre-magnetized flow channel is a spiral flow channel.

[0020] In some embodiments, the pre-magnetized pipeline is wound around the pre-magnetized magnet to form the flow channel with a changing direction.

[0021] In some embodiments, the pre-magnetization magnetic field includes 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 with time.

[0022] In some embodiments, the pre-magnetization magnet comprises an AC electromagnet, which forms the second part of the pre-magnetization magnetic field when energized.

[0023] In some embodiments, the pre-magnetization magnet comprises a DC electromagnet, which forms the first part of the pre-magnetization magnetic field when energized.

[0024] In some embodiments, the pre-magnetization pipe is a flexible hose, and the length of the portion located in the pre-magnetization magnetic field is adjusted by moving the pre-magnetization pipe.

[0025] In some embodiments, the fluorescence signal enhancement device further includes a flow channel component, wherein the flow channel component defines a droplet flow channel, and at least a portion of the droplet flow channel is located in the first magnetic field.

[0026] In some embodiments, the pre-magnetized flow channel is connected to the droplet flow channel, and the droplet flow channel is located after the pre-magnetized flow channel along the droplet flow direction.

[0027] In some embodiments, the magnet assembly includes a first magnet and a second magnet, wherein the first magnet is arranged on one side of the droplet flow channel; the second magnet is arranged on the other side of the droplet flow channel; wherein the length direction of the droplet flow channel is along the direction of cutting the magnetic flux lines between the first magnet and the second magnet.

[0028] In some embodiments, the flow channel assembly includes a microfluidic chip, which defines a chip flow channel for droplet flow within the chip, and the chip flow channel includes a sheath liquid inlet channel, a sample liquid inlet channel and a droplet flow channel. At least a portion of the droplet flow channel is located in the first magnetic field. The liquid inlet end of the sample liquid inlet channel is used to fill the droplets that have passed through the pre-magnetized magnetic field. The liquid outlet end of the sample liquid inlet channel and the liquid outlet end of the sheath liquid inlet channel are connected to the liquid inlet end of the droplet flow channel. The droplets that have passed through the pre-magnetized magnetic field are mixed with the sheath liquid and enter the droplet flow channel.

[0029] In some embodiments, the flow channel assembly also includes a support frame, which includes a base plate, a first side plate and a second side plate, and the first side plate and the second side plate are arranged opposite to each other; the microfluidic chip is located between the first side plate and the second side plate, and overlaps the upward side of the base plate.

[0030] In some embodiments, the fluorescence signal enhancement device further includes a carrier plate and a fixing assembly, wherein the carrier plate is provided with an installation window; and the fixing assembly is used to fix the flow channel assembly to the installation window.

[0031] In some embodiments, the fixing assembly includes a first clamping member and a second clamping member, wherein the first clamping member is used to fix the first end of the chip assembly; and the second clamping member is used to fix the second end of the chip assembly.

[0032] In some embodiments, the pre-magnetization component is fixed to the supporting plate.

[0033] In some embodiments, the magnet assembly includes a first magnet and a second magnet, wherein the first magnet is disposed on an inward side of the first side plate; and the second magnet is disposed on an inward side of the second side plate.

[0034] In some embodiments, the fluorescence signal detection device includes the above-mentioned fluorescence signal enhancement device, a laser component and a fluorescence detection component, wherein the laser component is used to emit laser light to the magnetic particles drawn into a linear shape, and the fluorescent markers in the droplets are excited by the laser to emit fluorescence; the fluorescence detection component is used to detect the fluorescence emitted by the fluorescent markers in the droplets.

[0035] In some embodiments, the laser component is disposed below the supporting plate, and the light emission direction is toward the portion of the droplet flow channel located in the first magnetic field; and / or, the fluorescence detection component is disposed below the supporting plate, and the detection direction is toward the portion of the droplet flow channel located in the first magnetic field.

[0036] In some embodiments, an observation window is provided on the bottom plate of the support frame, and at least the first part of the microfluidic chip corresponding to the observation window is made of a transparent material; wherein the light emission direction of the laser component is toward the observation window; and / or the detection position of the fluorescence detection component corresponds to the observation window.

[0037] In some embodiments, the droplet observation device includes the above-mentioned fluorescence signal enhancement device, a light source assembly and an imaging assembly, wherein the light source assembly has a light emission direction toward the droplets in the first magnetic field; and the imaging assembly has an imaging position toward the droplets in the first magnetic field.

[0038] In some embodiments, the light source assembly is disposed above the supporting plate, and the light emission direction is toward the portion of the droplet flow channel located in the first magnetic field; and / or, the imaging assembly is disposed below the supporting plate, and the light emission direction is toward the portion of the droplet flow channel located in the first magnetic field.

[0039] In some embodiments, the imaging assembly includes a high-speed camera, and the light source assembly is opened synchronously with a shutter of the high-speed camera.

[0040] In some embodiments, the bottom plate of the support frame is provided with an observation window, at least a first portion of the microfluidic chip corresponding to the observation window is made of a transparent material, and the imaging position of the imaging component faces the first portion of the observation window.

[0041] In some embodiments, at least the second portion of the upward side of the microfluidic chip corresponding to the observation window is made of a transparent material, and the light emitted by the light source assembly is directed toward the second portion of the microfluidic chip.

[0042] The fluorescent signal enhancement device, fluorescent signal detection device, and droplet observation device provided by the embodiments of the present disclosure can achieve the following technical effects:

[0043] By pre-magnetizing the droplets, the magnetic particles can be magnetized before entering the first magnetic field to form a clustered state. After entering the first magnetic field, the magnetized and clustered magnetic particles can be better pulled into a linear shape, so that the fluorescent substances in the particle clusters can be more fully excited by the laser, thereby improving the recognition accuracy of the droplets.

[0044] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] One or more embodiments are exemplarily described by corresponding drawings. These exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation. In addition,

[0046] Figure 1 is a structural schematic diagram of a fluorescence signal enhancement device provided by an embodiment of the present disclosure;

[0047] Figure 2 is a structural schematic diagram of another fluorescence signal enhancement device provided by an embodiment of the present disclosure;

[0048] Figure 3 Schematic diagram of the structure of a droplet recognition device provided by an embodiment of the present disclosure;

[0049] Figure 4 is a schematic structural diagram of another droplet recognition device provided by an embodiment of the present disclosure;

[0050] Figure 5 is the microstructure of the droplet that has not been pre-magnetized;

[0051] Figure 6 This is the microstructure of the droplet after pre-magnetization;

[0052] Figure 7 This is the microstructure of the droplet in the first magnetic field without pre-magnetization;

[0053] Figure 8 This is the microstructure of the pre-magnetized droplet in the first magnetic field;

[0054] Figure 9 is a graph of the fluorescence signal intensity of the droplet in the first magnetic field, wherein the left part is the fluorescence signal intensity when the droplet is not pre-magnetized, and the right part is the fluorescence signal intensity after the droplet is pre-magnetized;

[0055] Figure 10Schematic diagram of the structure of a microfluidic chip of a fluorescence signal enhancement device provided by an embodiment of the present disclosure;

[0056] Figure 11 Schematic diagram of the structure of a microfluidic chip of another fluorescence signal enhancement device provided by an embodiment of the present disclosure;

[0057] Figure 12 Schematic diagram of the structure of a fluorescence signal detection device provided by an embodiment of the present disclosure;

[0058] Figure 13 Schematic diagram of the structure of a droplet observation device provided by an embodiment of the present disclosure;

[0059] Figure 14 is a structural schematic diagram of another droplet observation device provided by an embodiment of the present disclosure;

[0060] Figure 15 yes Figure 14 A magnified schematic diagram of point A in the middle;

[0061] Figure 16 is a schematic structural diagram of an electrode assembly provided by an embodiment of the present disclosure;

[0062] Figure 17 is a schematic structural diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0063] Figure 18 is a schematic structural diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0064] Figure 19 is a schematic structural diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0065] Figure 20 is a schematic structural diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0066] Figure 21 is a schematic structural diagram of another electrode assembly provided by an embodiment of the present disclosure;

[0067] Figure 22 is a schematic diagram of a fluorescence signal detection method provided by an embodiment of the present disclosure;

[0068] Figure 23 is a schematic diagram of a droplet sorting method provided by an embodiment of the present disclosure;

[0069] Figure 24 is a schematic diagram of another droplet sorting method provided by an embodiment of the present disclosure;

[0070] Figure 25 Schematic diagram of a fluorescence signal detection device provided in an embodiment of the present disclosure.

[0071] Reference numerals:

[0072] 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: Chip 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 outlet channel; 3141: First liquid outlet; 315: Second liquid outlet channel; 3151: Second liquid outlet; 316: Positive electrode flow channel; 317: Negative electrode flow channel; 320: Support frame; 322: First side plate; 323: First side plate Two side panels; 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: carrier plate; 720: fixing assembly; 721: first clamping member; 722: second clamping member; 80: electrode unit; 810: positive electrode; 820: negative electrode; 831: positive electrode connector; 832: negative electrode connector; 840: electrode mounting plate; 850: first air pump; 860: second air pump; 870: first shielding electrode; 880: second shielding electrode; 900: processor; 901: memory; 902: communication interface; 903: bus. DETAILED DESCRIPTION

[0073] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0074] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe the embodiments of the present disclosure herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0075] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to having a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0076] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0077] Unless otherwise stated, the term "plurality" means two or more.

[0078] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0079] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0080] The term "magnetic particles" can be used interchangeably with "magnetic beads", where "magnetic particles" and "magnetic beads" refer to paramagnetic particles that can specifically bind to antigens, antibodies or secondary antibodies.

[0081] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0082] Antibodies are one of the body's key humoral immune mechanisms for defending against invasion by pathogens such as viruses and bacteria. Protective vaccines are a crucial weapon in curbing the spread of various pathogens. They not only specifically identify pathogens but also bind closely to antigens, effectively blocking damage to cells, tissues, and the body. Antibodies are produced by B cells and undergo multiple rounds of screening through the lymphatic system. Only a very small number of B cells undergo gene rearrangement to produce high-affinity antibodies. Effectively isolating and enriching B cells that secrete high-affinity antibodies is a challenge in antibody research.

[0083] Related technologies disclose a microfluidic chip device and a method of use for sorting fluorescently labeled cells based on magnetic field control. The microfluidic chip includes a sample channel, two sheath fluid channels, a first fluorescence detection area, a second fluorescence detection area, a magnetic field control system, a magnetic field-controlled cell sorting area, a target cell channel, and a waste liquid channel. Based on the fluorescent signal marked on the cells, the FACS system is combined with the magnetic field-controlled sorting system to realize automated cell sorting.

[0084] The problem with the related technology is that during the fluorescence recognition process, the distribution of the fluorescent substance in the target droplet is relatively dispersed, which makes the characteristic peak of the fluorescence signal unclear, thereby affecting the recognition accuracy of the cell.

[0085] In order to improve the recognition accuracy of droplets, combined with Figures 1 to 4 As shown, an embodiment of the present disclosure provides a fluorescence signal enhancement device for enhancing the fluorescence signal of a droplet. The fluorescence signal enhancement device includes a pre-magnetization component 100 and a magnet component 200, wherein the pre-magnetization component 100 is used to generate a pre-magnetization magnetic field, and the magnetic particles in the droplet are magnetized and agglomerated in the pre-magnetization magnetic field; the magnet component 200 is used to generate a first magnetic field, and the agglomerated magnetic particles in the droplet are pulled into a linear shape in the first magnetic field.

[0086] For example, the droplet sorting system provided by the embodiments of the present disclosure can be used to sort biological samples such as cells, bacteria, and viruses. The droplet includes at least one cell, bacterium, or virus, and a fluorescently identifiable marker.

[0087] As an optional embodiment, the fluorescence signal enhancement device provided in the embodiment of the present disclosure is applied to the following sample liquid: the sample liquid includes multiple droplets, each droplet contains at least one cell, multiple magnetic particles, multiple fluorescently labeled antigens and fluorescently labeled secondary antibodies.

[0088] After antigen recognition, cells produce a variety of antibodies, which can bind to multiple antigens. Magnetic particles have multiple functional groups on their surfaces that can bind to a variety of antibodies secreted by cells. Secondary antibodies bind only to specific antibodies. If a target particle cluster containing antigen, antibody, magnetic particles, and secondary antibody all bound together appears in a droplet, the cell in that droplet is considered a target cell capable of producing high-affinity antibodies, and the droplet is considered a target droplet.

[0089] To confirm whether a target particle cluster exists within a droplet, the antigens and antibodies within the target particle cluster can be fluorescently identified. Specifically, a first laser and / or a second laser are applied to the droplet. The fluorescent substance in the antigen emits a first fluorescence under the excitation of the first laser, while the fluorescent substance in the secondary antibody emits a second fluorescence under the excitation of the second laser. If the intensities or characteristic peaks of the first and / or second fluorescence meet pre-set conditions, the droplet is considered the target droplet.

[0090] In practice, fluorescent antigens and secondary antibodies are distributed throughout each droplet. In some cases, even if the secondary antibody in a particular droplet hasn't bound to the antibody, the laser can still excite the unbound antibody, producing a second fluorescence that can interfere with the judgment. In other cases, even if the secondary antibody in a particular droplet binds to the antibody, the irregular distribution of the target particle clusters can make the characteristic fluorescence peaks emitted by the fluorescent substances of the antigen and secondary antibody less distinct, easily leading to misjudgment.

[0091] Before or during laser excitation of the fluorescent substance, a magnetic field is applied to the droplet, causing the target particle clusters to align according to a specific pattern. This reduces misidentification of target droplets. Specifically, the magnetic particles are paramagnetic. The magnetic particles themselves are non-magnetic, preventing aggregation during or before sample incubation, which could affect binding between the magnetic particles and the antibody. Paramagnetic magnetic particles become magnetized in a magnetic field, exhibiting magnetic properties and distributing themselves along the magnetic flux lines of the field. The position of the magnetic particles changes, causing the particle clusters, which are key components of the magnetic particles, to align according to a specific pattern within the droplet. Unbound secondary antibodies do not follow this pattern. When laser light is applied to the droplet, the target particle clusters, which follow a specific pattern, emit fluorescence. If the first fluorescence characteristic peak within the particle cluster is prominent, identification is considered successful. Furthermore, if the second fluorescence characteristic peak meets pre-set conditions, the cell is considered to secrete antibodies that specifically bind to the secondary antibody, indicating that the droplet is a target droplet.

[0092] Unmagnetized magnetic particles are first magnetized upon entering a magnetic field. A magnetic domain is a region within a ferromagnetic material where the atomic magnetic moments (i.e., the spin magnetic moments of electrons) align, forming a localized magnetized region. In the absence of an external magnetic field, these domains are randomly arranged within the material, resulting in the material exhibiting no magnetism on a macroscopic scale. When an external magnetic field acts on the ferromagnetic material, the magnetic moments of these domains tend to align with the external field, causing the material to exhibit magnetism. The domains rearrange themselves along the direction of the magnetic flux lines in the magnetic field, causing the magnetic particles to appear magnetic on a macroscopic scale. If the direction of the magnetic flux lines varies significantly as the droplet flows, the magnetization effect on the magnetic particles is poor. If the direction of the magnetic flux lines varies little as the droplet flows, the initial position of the magnetic particles in the magnetic field is more likely to correspond to their position in the magnetic field after magnetization. In other words, after entering a magnetic field, unmagnetized magnetic particles are less likely to distribute according to a specific pattern or along a straight line or curve, affecting cell recognition results.

[0093] In order to make the magnetic particles distribute more regularly in the magnetic field, the fluorescence signal enhancement device provided in the embodiment of the present disclosure includes a pre-magnetization component 100.

[0094] The pre-magnetization component 100 is used to make the magnetic particles appear magnetic on a macroscopic scale, that is, to present an N pole and an S pole. Specifically, the pre-magnetization component 100 is used to generate a pre-magnetic magnetic field, and the magnetic particles are rearranged in the pre-magnetic magnetic field according to the direction of the magnetic flux lines of the pre-magnetic magnetic field, thereby showing magnetism on a macroscopic scale. It should be noted that during and after the magnetization of the magnetic particles, under the action of the magnetic field force and the Brownian motion of the magnetic particles, the magnetic particles approach each other and become agglomerated. The agglomerated state can be defined as the magnetic particles inside the droplet attracting each other and approaching each other.

[0095] The fluorescence signal enhancement device provided by the embodiment of the present disclosure also includes a magnet assembly 200. The magnet assembly 200 is located at the rear stage of the pre-magnetization assembly 100. The pre-magnetized magnetic particles enter the first magnetic field formed by the magnet assembly 200 along with the droplets. 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 so that the magnetic flux lines inside the magnetic particles tend to be in the same direction as the magnetic flux lines of the first magnetic field. In this case, when the magnetic flux lines in the first magnetic field are straight lines, the multiple magnetic particles are distributed along the straight lines, and when the magnetic flux lines in the first magnetic field are curved lines, the multiple magnetic particles are distributed along the curves. In addition, the multiple magnetic particles entering the first magnetic field are in a state of agglomeration, and under the action of the magnetic field force of the first magnetic field, the agglomerated magnetic particles are distributed along the same or adjacent magnetic flux lines in the first magnetic field. In this way, the distribution of the magnetic particles in the first magnetic field can be made more regular, which is conducive to reducing misjudgments caused by irregular distribution of magnetic particles, thereby improving the accuracy of droplet identification.

[0096] Combine Figure 5 As shown, the distribution of magnetic particles and particle clusters without pre-magnetization is relatively dispersed; combined with Figure 6 As shown, the distribution of the pre-magnetized magnetic particles and particle clusters is in an agglomerated state.

[0097] Combine Figure 7 As described above, after the droplets without pre-magnetization enter the first magnetic field, the particle clusters are pulled into multiple thin lines, combined with Figure 8 As shown in FIG, after the pre-magnetized droplets enter the first magnetic field, the particle cluster is pulled into a thick line.

[0098] Combine Figure 9 As shown, Figure 9 The peak on the left in the middle is the characteristic peak of fluorescence intensity after the unmagnetized droplet enters the first magnetic field, and the peak on the right is the characteristic peak of fluorescence signal after the premagnetized droplet enters the first magnetic field. It can be seen that the characteristic peak is more obvious after the premagnetized droplet enters the first magnetic field, due to the fluorescence signal recognition of the droplet.

[0099] By using the fluorescence signal enhancement device provided in the embodiment of the present disclosure, the pre-magnetization component 100 is set to allow the magnetic particles to be magnetized before entering the first magnetic field to form a clustered state. After entering the first magnetic field, the magnetized and clustered magnetic particles can be pulled into a linear shape, so that the fluorescent substance in the particle cluster can be more fully excited by the laser, thereby improving the recognition accuracy of the droplets.

[0100] Optionally, the magnetic field strength of the pre-magnetization magnetic field is greater than the magnetic field strength of the first magnetic field.

[0101] The higher the intensity of the pre-magnetization magnetic field, the faster the magnetic particles are magnetized. The lower the intensity of the first magnetic field, the less likely it is that the magnetic particles will be re-magnetized in the first magnetic field, which helps the magnetic particles in the droplets to be drawn into a linear shape in the first magnetic field.

[0102] The pre-magnetization of the magnetic particles in the droplets can be performed in a container or in a pipe. When performed in a container, the droplets are stationary. The container containing the droplets is placed in a pre-magnetization magnetic field, and the magnetic particles in the droplets are magnetized. This method facilitates the control of the magnetization of the magnetic particles. When performed in a pipe, the droplets are in a flowing state. The pipe through which the droplets flow is placed in a pre-magnetization magnetic field, and the magnetic particles in the droplets are magnetized during the flow. This method facilitates driving the droplets to flow and facilitates the entry of the pre-magnetized droplets into the subsequent first magnetic field.

[0103] Optionally, combined Figures 1 to 4As shown, the pre-magnetization assembly 100 includes a pre-magnetization pipeline 110 and a pre-magnetization magnet 120, wherein the pre-magnetization pipeline 110 defines a pre-magnetization flow channel for the flow of droplets; the pre-magnetization magnet 120 is used to generate a pre-magnetization magnetic field, and at least a portion of the pre-magnetization flow channel is located in the pre-magnetization magnetic field.

[0104] The pre-magnetization circuit 110 defines a first flow channel, and the pre-magnetization magnet forms a pre-magnetization magnetic field. At least a portion of the first flow channel is located in the pre-magnetization magnetic field, and the droplets are magnetized in the pre-magnetization magnetic field when flowing through the portion of the first flow channel located in the pre-magnetization magnetic field. The pre-magnetization component 100 includes a pre-magnetization circuit 110 and a pre-magnetization magnet, which facilitates the fluorescence signal enhancement device to magnetize the magnetic particles in the droplets and agglomerate the magnetic particles. Since the pre-magnetization of the droplets is performed in the pre-magnetization circuit 110, the droplets can be pre-magnetized while flowing. This allows the pre-magnetization of the magnetic particles in the droplets to be performed continuously, thereby improving the continuity of the pre-magnetization of the droplets by the fluorescence signal enhancement device.

[0105] Optionally, combined Figure 2 As shown, the pre-magnetization magnet includes a pre-magnetization coil 123, which 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. When the coil is energized, a pre-magnetization magnetic field is generated.

[0106] The pre-magnetization coil 123 is spirally wound around the pre-magnetization circuit 110. When energized, it forms an electromagnet that generates a pre-magnetization magnetic field. The axis of the pre-magnetization coil 123 is the line around which the pre-magnetization coil 123 spirals, and the two ends of the pre-magnetization circuit 110 serve as the north and south poles, respectively. This configuration helps reduce the volume of the pre-magnetization assembly 100 and allows the strength of the pre-magnetization magnetic field to be adjusted by adjusting the current intensity and / or the number of turns of the pre-magnetization coil 123.

[0107] Optionally, the pre-magnetized magnet includes a first pre-magnetized magnet 121 and a second pre-magnetized magnet 122 , wherein the first pre-magnetized magnet 121 is disposed on one side of the pre-magnetized pipeline 110 ; the second pre-magnetized magnet 122 is disposed on the other side of the pre-magnetized pipeline 110 .

[0108] The first pre-magnetized magnet 121 and the second pre-magnetized magnet 122 are positioned opposite each other, with the north pole of the first pre-magnetized magnet 121 facing the south pole of the second pre-magnetized magnet 122, or vice versa. Linear magnetic flux lines are formed between the first pre-magnetized magnet 121 and the second pre-magnetized magnet 122. When a droplet flows through the pre-magnetized magnets, the direction of the magnetic flux lines remains substantially unchanged, thereby enhancing the magnetization effect on the magnetic particles.

[0109] The first and second pre-magnetized magnets 122 are positioned opposite each other on either side of the pre-magnetized pipe 110. The magnetic force between the first and second pre-magnetized magnets 121, 122 acts on the droplets in the pre-magnetized pipe 110. The strength of the pre-magnetized magnetic field can be varied by changing the distance between the first and second pre-magnetized magnets 122. Furthermore, the pre-magnetized magnets and the pre-magnetized pipe 110 are separate components, making it easier for users to assemble and maintain the pre-magnetized assembly 100.

[0110] Optionally, the pre-magnetized magnet is used to generate a pre-magnetized magnetic field with a changing direction, and the magnetic particles in the droplets move and agglomerate under the action of the changing magnetic field force when in the pre-magnetized flow channel.

[0111] In the pre-magnetization magnetic field, the magnetic particles in the droplets are not only magnetized but also rotate and move under the influence of the magnetic force, causing them to agglomerate. While the magnetic particles can be magnetized in a relatively short time, agglomeration takes longer. Changing the direction of the pre-magnetization magnetic field intensifies the movement of the magnetic particles in the field, accelerating their agglomeration. This arrangement can enhance the agglomeration of magnetic particles in the droplets in the pre-magnetization magnetic field.

[0112] Optionally, the pre-magnetized magnet includes multiple magnet pairs, which are arranged close to the pre-magnetized flow channel, and magnetic flux lines are formed between each magnet pair. The directions of the magnetic flux lines of the multiple magnet pairs are different to form a pre-magnetized magnetic field with changing directions.

[0113] As an implementation form of generating a pre-magnetized magnetic field with a change in direction, the pre-magnetized magnet includes a plurality of magnet pairs, each magnet pair including two magnets with north and south poles arranged opposite to each other. The plurality of magnet pairs are arranged along the length direction of the pre-magnetized flow channel, and the two magnets of each magnet pair are respectively on both sides of the pre-magnetized flow channel. The directions of the magnetic flux lines inside the plurality of magnet pairs are different, so the direction of the magnetic force exerted on the droplets when flowing through the pre-magnetized flow channel also changes. Such an arrangement is conducive to the agglomeration of magnetic particles in the droplets in the pre-magnetized magnetic field.

[0114] Optionally, the plurality of magnet pairs are distributed in a spiral shape.

[0115] The multiple magnet pairs are arranged in a helical pattern similar to RNA molecules, so that the magnetic force exerted on the droplets when flowing through the pre-magnetization pipeline 110 rotates in one direction. This can better enable the magnetic particles to rotate and move in the pre-magnetization magnetic field, thereby causing agglomeration.

[0116] Optionally, the pre-magnetized magnet includes an electromagnet, and a pre-magnetized magnetic field with changing direction is formed by adjusting the current intensity and / or current direction of the electromagnet; or, the pre-magnetized magnet includes a coil, which is wound around the pre-magnetized pipeline 110, and a pre-magnetized magnetic field is generated when the coil is energized, and a pre-magnetized magnetic field with changing direction is formed by adjusting the current intensity and / or current direction of the coil.

[0117] Changing the direction of the electromagnet's current changes the direction of its magnetic field; changing the current intensity changes the intensity of its magnetic field. The pre-magnetization assembly 100 includes an electromagnet, and the pre-magnetization assembly 100 can generate a pre-magnetization magnetic field with varying directions by changing the direction and / or intensity of the current.

[0118] When the pre-magnetized magnet includes the pre-magnetized coil 123 wound around the pre-magnetized pipeline 110 , a pre-magnetized magnetic field with a changing direction can also be formed by changing the current direction and / or current intensity.

[0119] When the magnetic field strength and / or magnetic field direction of the pre-magnetization magnetic field changes, the magnetic particles in the droplets can be more fully magnetized and agglomerated, which is conducive to the magnetic particles being pulled into a wire shape in the first magnetic field.

[0120] Optionally, the pre-magnetized flow channel is a direction-changing flow channel, at least part of which is located in the pre-magnetized magnetic field, and the magnetic particles in the droplets move in the direction-changing flow channel under the force of the first magnetic field and agglomerate.

[0121] When the magnetic field direction remains unchanged, the pre-magnetized flow channel is a flow with changing direction. When the droplets flow in the pre-magnetized flow channel, the magnetism of the droplets can change due to the force of the pre-magnetized magnet in the pre-magnetized magnetic field, which can also accelerate the aggregation of the magnetism in the droplets in the pre-magnetized magnetic field.

[0122] It should be noted that when the direction and / or intensity of the magnetic field changes, the direction of the pre-magnetized flow channel also changes, which can further accelerate the movement of the magnetic particles in the droplets in the pre-magnetized magnetic field, thereby causing the magnetic particles in the droplets to agglomerate.

[0123] Optionally, the pre-magnetized flow channel includes a plurality of bent segments, and the plurality of bent segments are connected end to end to form a pre-magnetized flow channel with a changing direction.

[0124] As an implementation of a pre-magnetized flow channel with a changing direction, the pre-magnetized flow channel includes multiple curved segments. The multiple curved segments are U-shaped or S-shaped, and the multiple curved segments are connected end to end. This arrangement not only subjects the magnetic particles in the droplets to the forces of a changing magnetic field, but also increases the flow formation of the droplets in the pre-magnetized magnetic field, thereby enhancing the pre-magnetization effect and agglomeration effect of the magnetic particles in the droplets by increasing the length of time the droplets remain in the pre-magnetized magnetic field.

[0125] Optionally, the pre-magnetized flow channel is a spiral flow channel.

[0126] When the pre-magnetized flow channel is spiral, the droplets are also subject to centrifugal force. As the droplets follow the spiral flow channel, the antigens, antibodies, secondary antibodies, and magnetic particles in the droplets tend to move toward the outside of the pre-magnetized flow channel under the influence of centrifugal force. This not only facilitates the specific binding between the antigens, antibodies, secondary antibodies, and magnetic particles, but also promotes the aggregation of the magnetized magnetic particles.

[0127] Optionally, the pre-magnetization pipeline 110 is wound around the pre-magnetization magnet to form a flow channel with a changing direction.

[0128] The pre-magnetization pipe 110 is wound around the pre-magnetization magnet, and the pre-magnetization magnet can fix the pre-magnetization pipe 110, thereby improving the structural rigidity of the pre-magnetization assembly 100. In addition, the pre-magnetization pipe 110 is wound around the pre-magnetization magnet, which can reduce the volume of the pre-magnetization assembly 100.

[0129] The pre-magnetization line 110 is wound around the pre-magnetization magnet. First, if the size of the pre-magnetization magnet is limited, the length of the pre-magnetization line 110 can be increased, thereby increasing the time the droplets remain in the pre-magnetization magnetic field. This can improve the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles. Second, the pre-magnetization line 110 is wound around the pre-magnetization magnet, and the radial direction of the pre-magnetization line 110 is along the direction that cuts the magnetic flux lines of the pre-magnetization magnet. When the droplets flow in the pre-magnetization line 110, the magnetic flux lines acting on the magnetic particles are in substantially the same direction, which can further improve the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles.

[0130] Optionally, the pre-magnetization magnetic field includes 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 with time.

[0131] Magnetic particles in the droplet are magnetized in the pre-magnetization magnetic field. The magnetized magnetic shells aggregate during flow within and after leaving the pre-magnetization magnetic field. Changing the magnetic field direction of the pre-magnetization magnetic field is beneficial for agglomeration, while maintaining the same direction is beneficial for magnetization.

[0132] Therefore, the pre-magnetization magnetic field includes a first portion and a second portion. The magnetic field direction of the first portion remains constant, while the magnetic field direction of the second portion changes over time. This allows the magnetic particles to be magnetized in the first portion of the pre-magnetization magnetic field and to aggregate in the second portion. Although the magnetic particles are still magnetized in the second portion of the pre-magnetization magnetic field and aggregate in the first portion of the pre-magnetization magnetic field, this arrangement allows for a certain degree of separation between the pre-magnetization and aggregation of the magnetic particles, thereby improving the magnetization and aggregation effects of the magnetic particles.

[0133] Optionally, the pre-magnetization magnet includes an AC electromagnet, which forms the second part of the pre-magnetization magnetic field when energized.

[0134] The direction of the magnetic field of the alternating current electromagnet changes with the direction of the current, and the magnetic particles can move more in the second part of the pre-magnetization magnetic field, thereby agglomerating better.

[0135] Optionally, the pre-magnetization magnet includes a DC electromagnet, which forms the first part of the pre-magnetization magnetic field when energized.

[0136] The direction of the magnetic field of the DC electromagnet remains unchanged, and the intensity of the first part of the pre-magnetization magnetic field formed by the DC electromagnet is easy to adjust.

[0137] Optionally, the pre-magnetization pipe 110 is a flexible hose, and the length of the portion located in the pre-magnetization magnetic field can be adjusted by moving the pre-magnetization pipe 110 .

[0138] When it comes to pre-magnetizing magnetic particles, if the pre-magnetization time is too short, the magnetization effect is less pronounced, and the magnetic particles are less likely to achieve the desired agglomeration state. If the pre-magnetization time is too long, the magnetic particles aggregate tightly and are less likely to be pulled into a linear shape in the first magnetic field. Given a constant droplet flow rate, the length of the pre-magnetization conduit 110 within the pre-magnetization magnetic field determines the length of time the droplets remain in the pre-magnetization magnetic field. The required pre-magnetization time and magnetic field strength vary for different droplets. Given a constant magnetic field strength, the pre-magnetization duration of the droplets in the pre-magnetization magnetic field can be adjusted by adjusting the length of the portion of the pre-magnetization conduit 110 within the pre-magnetization magnetic field. This configuration facilitates user-defined pre-magnetization of the droplets. The adjustable length of the pre-magnetization conduit 110 within the pre-magnetization magnetic field allows the pre-magnetization time to be adjusted, thereby achieving a desired pre-magnetization effect for the magnetic particles in the droplets. Illustratively, as a length adjustment method, the pre-magnetization pipeline 110 is a flexible pipeline, and the length of the portion of the pre-magnetization pipeline 110 located in the pre-magnetization magnetic field is adjusted by changing the number of turns of the pre-magnetization pipeline 110 in the pre-magnetization magnetic field.

[0139] Optionally, at least a portion of the spiral of the pre-magnetization pipeline 110 is disposed in the pre-magnetization magnetic field.

[0140] By adopting such a configuration, the length of the pre-magnetization circuit 110 can be increased in the first aspect, thereby increasing the time that the droplets stay in the pre-magnetization magnetic field, thereby improving the pre-magnetization effect of the pre-magnetization magnetic field on the magnetic particles. It should be noted that in the initial stage when the magnetic particles enter the pre-magnetization magnetic field, they present an N pole and an S pole on a macroscopic scale. During the subsequent movement of the droplets, the magnetic particles can, under the action of the magnetic field force, make their internal magnetic flux lines tend to be consistent with the magnetic flux lines of the pre-magnetization magnetic field, that is, the magnetic particles adapt to the changes in the direction of the magnetic flux lines of the pre-magnetization magnetic field through their own rotation. Although the spiral form of the pre-magnetization circuit 110 causes the direction of the radial magnetic flux lines in the pre-magnetization circuit 110 to change multiple times, increasing the time that the magnetic particles stay in the pre-magnetization magnetic field can improve the pre-magnetization effect on the magnetic particles as a whole.

[0141] Optionally, combined Figures 1 to 4 As shown, the fluorescence signal enhancement device further includes a flow channel component, which defines a droplet flow channel 311, and at least a portion of the droplet flow channel 311 is located in the first magnetic field.

[0142] The flux of the droplet flow channel 311 is set to a size that can only pass one droplet at a time. The flow channel assembly cooperates with the first magnet 210, and the pre-magnetized droplets enter the droplet flow channel 311 of the flow channel assembly. Then, under the action of the first magnetic field, the agglomerated magnetic particles in the droplets are pulled into a linear shape. When the droplets are pre-magnetized in the container, the flow channel assembly has an opening for filling the droplets, and the opening is connected to the droplet flow channel 311. When the droplets are pre-magnetized in the pre-magnetization pipeline 110, the liquid outlet end of the pre-magnetization pipeline 110 is connected to the liquid inlet section of the droplet flow channel 311.

[0143] A flow channel assembly is provided, and the droplet flow channel 311 of the flow channel assembly is at least partially located in the first magnetic field, so that the droplets have a relatively fixed position when flowing through the first magnetic field, which is conducive to exciting and detecting fluorescent signals in the droplets.

[0144] Optionally, the pre-magnetized flow channel is connected to the droplet flow channel 311 , and the droplet flow channel 311 is located after the pre-magnetized flow channel along the droplet flow direction.

[0145] After passing through the pre-magnetization assembly 100, the droplets enter the droplet flow channel 311. The magnetic particles in the droplets flow along the droplet flow channel 311 for a distance, then are pulled into a linear shape. This arrangement facilitates fluorescent signal identification of the droplets, as well as observation and photography of the droplets. With this arrangement, the droplets flow continuously through the pre-magnetization flow channel and the droplet flow channel 311, improving the continuous operation capability of the fluorescence signal enhancement device.

[0146] Optionally, the magnet assembly 200 includes a first magnet 210 and a second magnet 220, wherein the first magnet 210 is arranged on one side of the droplet flow channel 311; the second magnet 220 is arranged on the other side of the droplet flow channel 311; wherein the length direction of the droplet flow channel 311 is along the direction of cutting the magnetic flux lines between the first magnet 210 and the second magnet 220.

[0147] The side of the first magnet 210 facing the second magnet 220 has opposite magnetic poles to the side of the second magnet 220 facing the first magnet 210. This creates a straight line of magnetic flux between the first magnet 210 and the second magnet 220, facilitating the alignment of multiple components, including magnetic particles, into a straight line. This enhances the fluorescence signal and improves droplet recognition accuracy.

[0148] Optionally, combined Figures 1 to 4As shown, the flow channel assembly includes a microfluidic chip, which defines a chip flow channel for droplets to flow therein. The chip flow channel includes a sheath liquid inlet channel 312, a sample liquid inlet channel 313 and a droplet flow channel 311. At least a portion of the droplet flow channel 311 is located in the first magnetic field. The liquid inlet end of the sample liquid inlet channel 313 is used to fill the droplets that have passed through the pre-magnetized magnetic field. The liquid outlet end of the sample liquid inlet channel 313 and the liquid outlet end of the sheath liquid inlet channel 312 are connected to the liquid inlet end of the droplet flow channel 311. The droplets that have passed through the pre-magnetized magnetic field are mixed with the sheath liquid and then enter the droplet flow channel 311.

[0149] The sheath fluid is a liquid medium used to focus water-in-oil droplets or samples. After being squeezed by the sheath fluid, the water-in-oil droplets or samples form a stable liquid flow environment together with the sheath fluid, so that the water-in-oil droplets or samples can pass through the droplet flow channel in a single column and roughly along the central axis of the droplet flow channel. Exemplarily, the sheath fluid is an oil phase. The liquid inlet end of the sample liquid flow channel 313 is used to fill the sample liquid, and a sample liquid injection port 3131 is provided in the sample liquid injection channel. The sample liquid contains water-in-oil droplets, and the droplets include at least a fluorescently identifiable marker. Exemplarily, the droplet sorting system provided in the embodiment of the present disclosure can be used to sort biological samples such as cells, bacteria, and viruses. The droplets include at least one cell, bacterium or virus, and a fluorescently identifiable marker.

[0150] The microfluidic chip 310 enables high-throughput droplet sorting, thereby improving the efficiency of experimental research. Microfluidic chips are low-cost, easy to use, and portable, reducing experimental costs. Microfluidic chip technology also enables non-destructive droplet sorting, ensuring the activity and integrity of the sample within the droplet.

[0151] The microfluidic chip 310 is configured with a sheath liquid inflow channel 312 and a sample liquid inflow channel 313. By controlling the pressure of the sheath liquid inflow channel 312 and the sample liquid inflow channel 313, the distance between two adjacent droplets entering the droplet flow channel 311 and the flow rate of the droplets can be changed.

[0152] The pre-magnetized droplets are water-in-oil droplets surrounded by sheath fluid. This oil-in-water droplet structure is intended to isolate antibodies and antigens from interfering with each other between adjacent droplets. After entering the sample liquid inflow channel 313 of the microfluidic chip 310, these water-in-oil droplets remix with the sheath liquid in the sheath liquid inflow channel 312, allowing the droplets to flow within the droplet flow channel 311 at a predetermined flow rate and predetermined distance. This arrangement facilitates the identification, observation, and sorting of droplets within the microfluidic chip 310.

[0153] Optionally, the microfluidic chip 310 is further configured with a pre-magnetized flow channel. The portion of the microfluidic chip 310 configured with the pre-magnetized flow channel serves as the aforementioned pre-magnetized pipeline 110 . After the droplets flow through the pre-magnetized flow channel, they enter the sample liquid inflow channel 313 .

[0154] By adopting such a configuration, the integration level of the liquid drop recognition device can be improved, thereby reducing the cost of the liquid drop recognition device.

[0155] Optionally, the pre-magnetized magnet includes a first pre-magnetized magnet 121 and a second pre-magnetized magnet 122 , and the first pre-magnetized magnet 121 and the second pre-magnetized magnet 122 are respectively disposed on the upper and lower surfaces of the microfluidic chip 310 .

[0156] With this arrangement, droplets flowing in the pre-magnetized flow flow in a direction that cuts the magnetic flux lines of the pre-magnetized magnets, facilitating magnetization of the magnetic particles in the droplets. Furthermore, the distance between the magnetic particles and the first and second pre-magnetized magnets 122 does not change significantly as the droplets flow. This reduces or prevents sample damage caused by the magnetized magnetic particles squeezing the droplets as they move toward the first or second pre-magnetized magnets 121, 122.

[0157] Optionally, combined Figures 12 to 15 As shown, the flow channel assembly also includes a support frame 320, which includes a bottom plate, a first side plate 322 and a second side plate 323, and the first side plate 322 and the second side plate 323 are arranged opposite to each other; the microfluidic chip is located between the first side plate 322 and the second side plate 323, and overlaps the upward side of the bottom plate.

[0158] The support frame 320 is used to secure the microfluidic chip 310. Specifically, the bottom of the microfluidic chip 310 is attached to the bottom plate of the support frame 320, and the two side ends of the microfluidic chip 310 are respectively clamped to the first side plate 322 and the second side plate 323 of the support frame 320. This arrangement facilitates the securement of the microfluidic chip 310 and facilitates the identification and observation of droplets in the droplet flow channel 311.

[0159] Optionally, the fluorescence signal enhancement device further includes a carrier plate 710 and a fixing assembly 720 , wherein the carrier plate 710 is provided with an installation window; and the fixing assembly 720 is used to fix the flow channel assembly to the installation window.

[0160] The chip assembly 300 is fixed to the mounting window, and the droplet flow channel 311 of the microfluidic chip 310 is exposed on both the downward side and the upward side, which is conducive to fluorescent identification and observation of droplets in the droplet flow channel 311.

[0161] Optionally, the fixing assembly 720 includes a first clamping member 721 and a second clamping member 722 , wherein the first clamping member 721 is used to fix the first end of the chip assembly 300 ; the second clamping member 722 is used to fix the second end of the chip assembly 300 .

[0162] The chip assembly 300 can be better fixed to the carrier board 710 by clamping the two ends of the chip assembly 300 with the first clamping member 721 and the second clamping member 722 .

[0163] Optionally, the pre-magnetization assembly 100 is fixed to the supporting plate 710 .

[0164] Such an arrangement not only facilitates the installation of the pre-magnetization assembly 100 , but also helps the user to adjust the length of the pre-magnetization pipeline 110 in the pre-magnetization magnetic field.

[0165] Optionally, the magnet assembly 200 includes a first magnet 210 and a second magnet 220 , wherein the first magnet 210 is disposed on an inward side of the first side plate 322 ; and the second magnet 220 is disposed on an inward side of the second side plate 323 .

[0166] 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 beneficial for fixing the magnet assembly 200 .

[0167] Combine Figures 1 to 15 As shown, an embodiment of the present disclosure provides a fluorescence signal detection device, including the above-mentioned fluorescence signal enhancement device, a laser component and a fluorescence detection component 500, wherein the laser component is used to emit laser light to the magnetic particles drawn into a linear shape, and the fluorescent markers in the droplets are excited by the laser light to emit fluorescence; the fluorescence detection component 500 is used to detect the fluorescence emitted by the fluorescent markers in the droplets.

[0168] After a droplet flows through the first section of the droplet flow channel 311, multiple particle clusters composed of magnetic particles within the droplet form linear lines. At this point, a laser assembly emits an excitation laser to the droplet, causing the antigens and secondary antibodies within the multiple particle clusters to fluoresce. By measuring the fluorescence intensity of the antigens and the secondary antibodies, it can be determined whether the droplet is the target droplet. This setup facilitates fluorescent identification of droplets and improves droplet identification accuracy.

[0169] Optionally, the laser component is arranged below the carrier plate 710, and the light emission direction is toward the portion of the droplet flow channel 311 located in the first magnetic field; and / or, the fluorescence detection component 500 is arranged below the carrier plate 710, and the detection direction is toward the portion of the droplet flow channel 311 located in the first magnetic field.

[0170] The laser assembly and the fluorescence detection assembly 500 are disposed below the carrier plate 710 and do not block the microfluidic chip, which is beneficial for users to observe the droplets in the droplet flow channel 311 .

[0171] Optionally, an observation window is provided on the bottom plate of the support frame 320, and at least the first part of the microfluidic chip corresponding to the observation window is made of a transparent material; wherein the light emission direction of the laser component is toward the observation window; and / or, the detection position of the fluorescence detection component 500 corresponds to the observation window.

[0172] Such a configuration is beneficial for the laser to act on the particle clusters in the droplets and for the fluorescence detection component 500 to receive the fluorescence signals of the particle clusters.

[0173] Optionally, the fluorescence detection assembly 500 includes a photomultiplier tube.

[0174] The photomultiplier tube can amplify the light 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 recognition.

[0175] Optionally, the fluorescence detection assembly 500 includes a first photomultiplier tube 510 and a second photomultiplier tube 520 , wherein the first photomultiplier tube 510 is used to detect the fluorescence signal of the antigen, and the second photomultiplier tube 520 is used to detect the fluorescence signal of the secondary antibody.

[0176] By detecting the two fluorescent signals through the first photomultiplier tube 510 and the second photomultiplier tube 520 , interference between the fluorescent signals can be reduced or avoided, which is beneficial to improving the accuracy of droplet recognition.

[0177] Optionally, the laser assembly includes a first laser light source 410 and a second laser light source 420 , wherein the first laser light source 410 is used to excite the fluorescent substance of the antigen, and the second laser light source 420 is used to excite the fluorescent substance of the secondary antibody.

[0178] By respectively exciting the antigen and the secondary antibody fluorescent substances by the first laser light source 410 and the second laser light source 420, the droplet recognition device can obtain more accurate fluorescence information, which is helpful for the droplet recognition device to determine whether the droplet is a target droplet.

[0179] Optionally, the laser assembly further includes an optical coaxial system 430 , which is configured to transmit light emitted by the first laser light source 410 and the second laser light source 420 to the observation window.

[0180] The laser assembly includes a coaxial optical system 430, which allows for unrestricted installation of the first and second laser sources 410 and 420, facilitating miniaturization of the droplet recognition device. The coaxial optical system 430 provides high optical axis alignment, minimizing laser transmission loss and increasing laser transmission efficiency.

[0181] Optionally, the light emitted by the laser assembly is directed toward the observation window.

[0182] Such a setting is beneficial for the laser component to excite the fluorescent substance in the particle cluster.

[0183] Optionally, the detection position of the fluorescence detection component 500 corresponds to the observation window.

[0184] Such a setting is beneficial for the fluorescence detection device to detect the fluorescence signal in the droplet.

[0185] Combine Figures 1 to 15 As shown, an embodiment of the present disclosure provides a droplet observation device, including the above-mentioned fluorescence signal enhancement device, a light source component 620 and an imaging component, wherein the light source component 620 has a light emission direction toward the droplets in the first magnetic field; and the imaging component has an imaging position toward the droplets in the first magnetic field.

[0186] The imaging component can capture image information of samples within target droplets, facilitating observation and analysis. The imaging component can also capture image information of suspected target droplets, allowing users to adjust the droplet recognition device's parameters based on the image of the suspected target droplet, further improving droplet recognition accuracy.

[0187] Optionally, the imaging assembly includes a high-speed camera 610 .

[0188] The high-speed camera 610 can still obtain a relatively clear droplet image when the droplets flow at high speed. The imaging component includes the high-speed camera 610, which can increase the speed of the droplet flow in the droplet observation device.

[0189] Optionally, the light source assembly 620 is disposed above the carrier plate 710, and the light emission direction is toward the portion of the droplet flow channel 311 located in the first magnetic field; and / or, the imaging assembly is disposed below the carrier plate 710, and the light emission direction is toward the portion of the droplet flow channel 311 located in the first magnetic field.

[0190] Light source assembly 620 illuminates from above, creating a silhouette image of the droplet in high-speed camera 610. The image's brightness and darkness can still be used to reconstruct the image information of the sample within the droplet. Compared to emitted light imaging, this method provides better depth-directed image information of the droplet. Furthermore, the top-down illumination provided by light source assembly 620 prevents direct light from reaching the user's eyes.

[0191] The imaging device is disposed below the carrier plate 710 , which can reduce or avoid blocking the droplet flow channel 311 , and is beneficial for users to monitor the operating status of the droplet observation device with the naked eye.

[0192] Optionally, the light source assembly 620 is opened synchronously with the shutter of the high-speed camera 610 .

[0193] The light source assembly 620 is activated only when the shutter of the high-speed camera 610 is open, which can reduce light pollution of the light source assembly 620 and increase the service life of the light source assembly 620.

[0194] Optionally, an observation window is provided on the bottom plate of the support frame 320 , at least a first portion of the microfluidic chip corresponding to the observation window is made of a transparent material, and the imaging position of the imaging component faces the first portion of the observation window.

[0195] This facilitates the imaging device to acquire the droplet image and can reduce or avoid the obstruction of the microfluidic chip by the imaging device.

[0196] Optionally, the fluorescent identification component is disposed below the carrying plate 710 .

[0197] Likewise, this can reduce the influence of ambient light on the fluorescent recognition component. In addition, the carrier plate 710 also serves as a protective plate for the fluorescent recognition component, preventing the fluorescent recognition component from being displaced or damaged when the user is using the droplet recognition device.

[0198] Optionally, at least the second portion of the upward side of the microfluidic chip corresponding to the observation window is made of a transparent material, and the light emitted by the light source assembly 620 is directed toward the second portion of the microfluidic chip.

[0199] The microfluidic chip can be entirely transparent, which facilitates fluorescent signal recognition of droplets in the droplet flow channel 311 and the acquisition of images of the droplets within the droplet flow channel 311. The microfluidic chip can also be partially transparent. When the microfluidic chip is partially transparent, at least the portion corresponding to the observation window is transparent. This facilitates imaging by the imaging device and visual observation of the droplets in the droplet flow channel 311 by the user.

[0200] An embodiment of the present disclosure also provides a droplet sorting system, which includes a flow channel component, the above-mentioned fluorescence signal enhancement device or fluorescence signal detection device and a sorting device, wherein the flow channel component defines a droplet flow channel 311 for droplet flow, a first liquid outlet flow channel 314 and a second liquid outlet flow channel 315; the fluorescence signal enhancement device is used to generate a pre-magnetization magnetic field and a first magnetic field, and 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 identification device is used to excite the droplets to emit fluorescence and mark the droplets that meet the fluorescence conditions as target droplets; the sorting device is arranged corresponding to the liquid outlet section of the droplet flow channel 311, and the target droplets flowing through the liquid outlet section of the droplet flow channel 311 enter the first liquid outlet flow channel 314 under the deflection action of the sorting device, and the non-target droplets enter the second liquid outlet flow channel 315.

[0201] The flow channel assembly defines a droplet flow channel 311, a first outlet flow channel 314, and a second outlet flow channel 315 for the flow of droplets. The liquid inlets of the first and second outlet flow channels 314 and 315 are connected to the liquid outlet of the droplet flow channel 311. Fluorescent signal recognition of droplets is performed in the droplet flow channel 311. After recognition, target droplets flow out of the first outlet flow channel 314, while non-target droplets flow out of the second outlet flow channel 315.

[0202] The droplet sorting system provided by the embodiment of the present disclosure also includes a fluorescent signal enhancement device and an identification device to identify target droplets. The fluorescent signal enhancement device is used to enhance the fluorescent signal of the droplets so that the target droplets can be easily identified by the identification device in the droplet flow channel 311. Specifically, the fluorescent signal enhancement device is used to generate a pre-magnetization magnetic field and a first magnetic field. The pre-magnetization magnetic field is used to make the magnetic particles appear magnetic on a macroscopic level, that is, to present N poles and S poles. Specifically, the magnetic particles are rearranged in the pre-magnetization magnetic field according to the direction of the magnetic flux lines of the pre-magnetization magnetic field in the secondary cycle, thereby showing magnetism on a macroscopic level. It should be noted that during the magnetization process of the magnetic particles and after magnetization, under the action of the magnetic field force and the Brownian motion of the magnetic particles, the magnetic particles approach each other and become agglomerated. The agglomerated state can be defined as a distance between at least two magnetic particles that is less than or equal to the diameter of a droplet.

[0203] Using the droplet sorting system provided by the embodiment of the present disclosure, since the fluorescence signal of the droplets is enhanced, the fluorescence signal of the target droplets and the fluorescence signal of the non-target droplets are more clearly distinguished, which can improve the accuracy of droplet sorting.

[0204] Optionally, the sorting device includes a sorting electromagnet, which is arranged in the liquid outlet section of the droplet flow channel 311. The sorting electromagnet is activated when the target droplet flows through the liquid outlet section of the droplet flow channel 311 to deflect the target droplet to the first liquid outlet channel 314 under the action of the magnetic field force.

[0205] The sorting electromagnet corresponds to the liquid outlet section of the droplet flow channel 311 and is located on the side where the first liquid outlet flow channel 314 is located. When the target droplet flows through the liquid outlet section of the droplet flow channel 311, the sorting electromagnet is energized. After the sorting electromagnet is energized, it has a pulling effect on the magnetic particles in the droplet, thereby deflecting the target droplet to the first liquid outlet flow channel 314. With such a setting, the sorting of target droplets can be conveniently achieved. It should be noted that when non-target droplets flow through the liquid outlet section of the droplet flow channel 311, the sorting electromagnet is not energized, and the non-standard droplets flow to the second droplet flow channel 311 under the action of inertia.

[0206] Optionally, the sorting device also includes a sorting electromagnet, which is arranged in the liquid outlet section of the droplet flow channel 311. The sorting electromagnet is activated when non-target droplets flow through the liquid outlet section of the droplet flow channel 311 so that the non-target droplets are deflected to the second liquid outlet channel 315 under the action of the magnetic field force.

[0207] In this case, when the target droplet flows through the liquid outlet end of the droplet flow channel 311 , the sorting electromagnet is not energized, and the target droplet flows toward the first liquid outlet flow channel 314 under the action of inertia.

[0208] With this arrangement, the magnetic particles in the target droplet will not be affected by the magnetic field force, which can reduce or prevent the magnetic particles from damaging the sample in the droplet when moving under the action of the magnetic field force.

[0209] Optionally, combined Figure 1 As shown, the sorting device includes a first air pump 850, which is arranged in the first liquid outlet channel 314. The first air pump 850 is configured to apply positive pressure to the first liquid outlet channel 314 when non-target droplets flow through the liquid outlet section of the droplet channel 311.

[0210] When the first air pump 850 is operating, it applies positive pressure to the first liquid outlet channel 314. This creates a certain pressure difference between the first liquid outlet channel 314 and the second liquid outlet channel 315. When non-target droplets flow through the outlet section of the droplet channel 311, they are deflected toward the second liquid outlet channel 315 due to the pressure difference. The air pump has a fast response speed, which can achieve high-speed droplet sorting. In addition, when the air pump applies positive pressure to the first liquid outlet channel 314, the droplets are evenly stressed, and the sample in the droplets is not easily damaged.

[0211] It should be noted that the shape of the flow channel can be designed so that target droplets and non-target droplets enter the first liquid outlet flow channel 314 when the first air pump 850 is not operating. In this way, target droplets can enter the first liquid outlet flow channel 314 and non-target droplets can enter the second liquid outlet flow channel 315 simply by starting and stopping the first air pump 850. Exemplarily, the shape of the flow channel is such that the liquid inlet section of the first liquid outlet flow channel 314 is located on the extension line of the liquid outlet section of the droplet flow channel 311, and the liquid inlet section of the second liquid outlet flow channel 315 forms an angle of less than or equal to 150° with the liquid outlet end of the droplet flow channel 311.

[0212] Optionally, the sorting device includes a second air pump 860 , which is disposed in the second liquid outlet channel 315 . The second air pump 860 is configured to apply positive pressure to the second liquid outlet channel 315 when the target droplets flow through the sorting device.

[0213] When the second air pump 860 is operating, it applies positive pressure to the second liquid outlet channel 315. This creates a certain pressure differential between the first liquid outlet channel 314 and the second liquid outlet channel 315. This pressure differential causes target droplets to flow through the outlet section of the droplet channel 311 and be deflected toward the first liquid outlet channel 314. This allows for high-speed droplet sorting and reduces the risk of damage to the sample within the target droplets as they are deflected.

[0214] It should be noted that the shape of the flow channel can be designed so that target droplets and non-target droplets enter the second liquid outlet flow channel 315 when the second air pump 860 is not operating. In this way, target droplets can enter the first liquid outlet flow channel 314 and non-target droplets can enter the second liquid outlet flow channel simply by starting and stopping the second air pump 860. The shape of the flow channel is, for example, such that the liquid inlet section of the second liquid outlet flow channel 315 is located on the extension line of the liquid outlet section of the droplet flow channel 311, and the liquid inlet section of the first liquid outlet flow channel 314 forms an angle of less than or equal to 150° with the liquid outlet end of the droplet flow channel 311.

[0215] Furthermore, the sorting device can be equipped with both the aforementioned first air pump 850 and the second air pump 860. When the sorting device includes the first air pump 850 and the second air pump 860, target droplets enter the first outlet channel 314 under the action of a pressure difference, while non-target droplets enter the second outlet channel 315 under the action of a pressure difference. This allows for better droplet sorting.

[0216] Optionally, combined Figure 10 、 Figure 11 、 Figure 19 、 Figure 20 As shown, the sorting device includes a positive electrode 810 and a negative electrode 820. The positive electrode 810 is arranged on the side where the first outlet channel of the droplet flow channel is located; the negative electrode 820 is arranged on the side where the first outlet channel of the droplet flow channel is located. When the positive electrode 810 and the negative electrode 820 are energized, an electric field is formed to act on the outlet section of the droplet flow channel 311, and the target droplet is deflected to the first outlet channel 314 under the action of the electrophoretic force.

[0217] The length of the droplet flow channel is the direction of droplet flow, which serves as the axial direction of the droplet flow channel. Using the length of the droplet flow channel as a dividing line, the droplet flow channel divides the plane in which it lies into two regions: one region is the first side, and the other region is the second side. The first outlet flow channel is located in the first region, and the positive and negative electrodes are also located in the first region. The first outlet flow channel, the positive and negative electrodes are located on the same side of the droplet flow channel.

[0218] Driven by external force, the droplets flow along the droplets, flowing from the liquid inlet end of the droplet flow channel to the liquid outlet section of the droplet flow channel. When the droplets flow to the liquid outlet section of the droplet flow channel, they enter the range of action of the electrode assembly. When the electrode assembly is energized, an electric field is formed, and the droplets are deflected toward the side close to the positive electrode 810 and the negative electrode 820 under the action of the electric field force. When the droplets continue to flow under the action of external force, they are more likely to enter the first liquid outlet flow channel because they are closer to the side where the first liquid outlet flow channel is located. In this process, it can be considered that the target droplets are deflected by the electrophoretic force, so that they can enter the first liquid outlet flow channel.

[0219] Optionally, combined Figure 11 As shown, the sorting device includes a plurality of positive electrodes 810 and a plurality of negative electrodes 820 , wherein the plurality of positive electrodes 810 and the plurality of negative electrodes 820 are alternately arranged and the plurality of negative electrodes 820 are connected.

[0220] Multiple positive electrodes and multiple negative electrodes are alternately arranged, forming an electric field between adjacent positive and negative electrodes. For a single droplet, sequentially energizing the multiple positive electrodes can pull the droplet toward the positive or negative electrode. With this arrangement, the multiple positive and negative electrodes can pull the droplet multiple times, deflecting the target droplet toward the first outlet channel. This can mitigate or prevent the droplet from being broken by excessive electrophoretic forces. Furthermore, the pull of multiple positive and negative electrodes can increase the throughput of droplet sorting.

[0221] It should be noted that the positive and negative electrodes can be supplied with alternating current. When supplied with alternating current, the alternating electric field between the positive and negative electrodes can also generate an electrophoretic force to deflect the droplet. In this case, the positive and negative electrodes are used only to distinguish opposite electrodes and to limit the positive electrode to only positive direct current and the negative electrode to only negative direct current.

[0222] By simply controlling the power on and off of multiple positive electrodes, electrophoretic forces can be applied to the droplets in sequence, causing them to deflect. Connecting multiple negative electrodes simplifies the installation of the negative electrodes.

[0223] Optionally, the sorting device includes a plurality of positive electrodes and two negative electrodes, and the two negative electrodes are located on both sides of the plurality of positive electrodes.

[0224] When energized, any of the multiple positive electrodes forms an electric field with the two negative electrodes. When the distances between the positive electrode and the two negative electrodes are different, the target droplet is deflected toward the first outlet channel by the electrophoretic force. The combination of multiple positive electrodes and two negative electrodes reduces the number of negative electrodes, thus simplifying their placement.

[0225] Optionally, the sorting device includes a plurality of positive electrodes 810 , and the distances between the plurality of positive electrodes 810 and the droplet flow channel 311 are not completely the same.

[0226] The sorting device includes a plurality of positive electrodes 810, which can form an electric field with a certain gradient. In the electric field, the droplets tend to move in the direction of the electric field gradient, thereby better deviating to the corresponding flow channel.

[0227] Optionally, the plurality of positive electrodes are activated one after another when the target liquid droplet flows through the liquid outlet section of the liquid droplet flow channel.

[0228] If a droplet is simultaneously subjected to the electrophoretic forces of multiple electric fields, its movement intention will become unclear. By activating multiple positive electrodes sequentially, the target droplet is deflected by only one electric field within a given period of time. This arrangement facilitates the sorting device to deflect the target droplet to the first outlet channel.

[0229] Optionally, combined Figures 16 to 21 As shown, 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, wherein the electrode unit includes one or more positive electrodes 810 and two negative electrodes 820, and the positive electrode 810 is 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 the two negative electrodes 820 are respectively located on both sides of the one or more positive electrodes 810.

[0230] The electrode assembly provided by the embodiments of the present disclosure can be applied to a sorting device or a droplet sorting system.

[0231] The sorting device or droplet sorting system has the function of identifying target droplets, and the electrode assembly is used to drive the target droplets to move toward the target side. At the electrode assembly, when the electrode is energized, the surface tension of the droplet will be affected by the surface charge, and the change in surface tension will cause the droplet shape to change. When the droplet shape changes, it moves in a directional manner in the droplet flow channel, that is, it 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 due to the action of the electrophoretic force.

[0232] It should be noted that the positive and negative electrodes can be supplied with alternating current. When supplied with alternating current, the alternating electric field between the positive and negative electrodes can also generate an electrophoretic force to deflect the droplet. In this case, the terms "positive electrode" and "negative electrode" are used merely to distinguish opposing electrodes and do not limit the positive electrode to being supplied with only positive direct current or the negative electrode to being supplied with only negative direct current.

[0233] Specifically, the droplet sorting system includes a sheath liquid inlet channel 312 , a sample liquid inlet channel 313 , a droplet channel 311 , a first liquid outlet channel 314 , and a second liquid outlet channel 315 .

[0234] The sheath liquid inflow channel 312 is used to fill the sheath liquid and has a sheath liquid injection port 3121. The sample liquid inflow channel 313 has a sample liquid injection port 3131 formed therein and is used to fill the sample liquid at its inlet end.

[0235] Illustratively, the recognition markers include multiple magnetic particles, multiple fluorescently labeled antigens, and fluorescently labeled secondary antibodies. After the antigen is recognized, the cell produces a variety of antibodies, which can bind to these antibodies. The magnetic particles have multiple functional groups on their surfaces that can bind to a variety of antibodies secreted by the cell. The secondary antibody only binds to specific antibodies. If a target particle cluster containing antigens, antibodies, magnetic particles, and secondary antibodies all binds together appears in a droplet, the cell in that droplet is considered a target cell capable of producing high-affinity antibodies, and the droplet is considered a target droplet.

[0236] The water-in-oil droplets in the sample fluid are used to isolate adjacent cells and are further mixed with the sheath fluid in the sheath fluid inflow channel, thereby flowing in the droplet flow channel 311 at a preset flow rate and a preset adjacent distance.

[0237] This facilitates the droplet sorting system to identify, observe and sort droplets in the droplet.

[0238] In the process of pulling the target droplet toward the target side of the droplet flow channel, if the applied force is small and the action time is short, the target droplet is not easily deflected. If the applied force is large, the droplet is easily broken. The electrode assembly provided in the embodiment 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, and the two negative electrodes are located on both sides of the one or more positive electrodes.

[0239] The electrode unit's one or more positive electrodes and two negative electrodes each form an electric field that acts on the target droplet. As the target droplet flows through the electrode assembly, it experiences a uniform, continuous pulling force, deflecting it toward the target side of the droplet flow path. Because the electric field formed by the positive and two negative electrodes has a wide range of action, the droplets within the target droplet are less likely to be broken apart. The electric field formed by the electrode unit acts for a longer period of time, making it easier for the target droplet to be deflected toward the target side.

[0240] When the electrode unit includes a positive electrode, the positive electrode and the two negative electrodes form two electric fields. The two electric fields are located on both sides of the positive electrode, making it difficult for electric field superposition or electric field interference to occur.

[0241] Using the electrode assembly provided in the embodiment of the present disclosure, the electrode unit can provide continuous and uniform pulling force for the target droplets, thereby allowing the droplets to pass through the droplet flow channel at a higher speed, which can significantly improve the droplet flux; the pulling force is provided to the target droplets through the multiple electric fields of the electrode unit, and the pulling force on the target droplets is relatively gentle, and the droplets are not easily broken.

[0242] Optionally, combined Figure 16 、 Figure 17 As shown, the electrode unit includes a plurality of positive electrodes, and two negative electrodes are respectively located on both sides of the plurality of positive electrodes.

[0243] When the electrode unit includes multiple positive electrodes, the multiple positive electrodes form multiple electric fields with the two negative electrodes respectively. When the target droplet flows through the electrode assembly, the electrophoretic force it is subjected to first gradually increases and then gradually decreases, and the target droplet is deflected more fully in the droplet flow channel.

[0244] Optionally, along the flow direction of the liquid droplets, the distances between the plurality of positive electrodes and the liquid droplet flow channel gradually increase.

[0245] When a target droplet flows through the electrode unit, it deflects toward the first side of the droplet flow channel under the action of the deflection force applied by the electrode assembly. The target droplet gradually decreases in distance from the multiple positive electrodes, and the electric field force it is subjected to gradually increases. The gradually increasing distance between the multiple positive electrodes and the droplet flow channel can ensure that the target droplet is subjected to uniform force as it flows through the electrode assembly. In addition, using this arrangement, the multiple positive electrodes can be supplied with substantially equal voltages, which facilitates voltage control of the multiple positive electrodes.

[0246] Optionally, along the flow direction of the droplet, the voltages of the plurality of positive electrodes gradually decrease.

[0247] This arrangement allows the force applied to the target droplet to remain essentially constant as it flows through the electrode assembly, thereby reducing the risk of the droplet being broken. Furthermore, by gradually decreasing the voltage across the multiple positive electrodes, the multiple positive and negative electrodes of the electrode assembly can be placed as close as possible to the droplet flow path, facilitating the placement of multiple positive and negative electrodes.

[0248] Optionally, combined Figure 17 As shown, the electrode assembly includes a plurality of electrode units 80, and the plurality of electrode units 80 are arranged on a first side of the droplet flow channel.

[0249] The electrode assembly includes multiple electrode units, which can further increase the range of action of the electric field formed by the electrode assembly. When the droplet flow rate is constant, the time the target droplet flows in the liquid outlet section of the droplet flow channel increases, thereby increasing the time the target droplet is affected by the electric field force of the electrode assembly. This allows the electrode assembly to pass 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. When the voltage of the electrode assembly is constant, the droplets can be allowed to pass through at a higher flow rate, which can increase the number of droplets sorted per unit time, that is, improve the sorting flux of the droplet sorting system.

[0250] Optionally, along the flow direction of the droplet, the distance between the plurality of electrode units and the droplet flow channel gradually increases.

[0251] When a target droplet flows through an electrode unit, it is deflected toward the first side of the droplet flow channel by the deflection force applied by the electrode assembly. The target droplet gradually decreases in distance from the electrode unit, and the electric field force it experiences gradually increases. By gradually increasing the distance between multiple electrode units and the droplet flow channel, the target droplet is subjected to uniform force as it flows through the electrode assembly. Furthermore, using this arrangement, the multiple electrode units can be supplied with substantially equal voltages, facilitating voltage control across the multiple electrode units.

[0252] Optionally, along the flow direction of the droplet, the voltage of the positive electrodes of the plurality of electrode units gradually decreases.

[0253] This ensures that the force applied to the target droplets remains essentially constant as they flow through the electrode assembly, reducing the risk of the droplets being broken. Furthermore, by gradually decreasing the voltages of the multiple positive electrodes, the multiple positive and negative electrodes of the electrode assembly can be placed as close to the droplet flow path as possible, facilitating the placement of multiple positive and negative electrodes.

[0254] Optionally, combined Figure 18 As shown, two adjacent electrode units 80 share a negative electrode 820 .

[0255] Two adjacent electrode units share a negative electrode, which reduces the number of negative electrodes and thus the cost of the electrode assembly. It also ensures that the electrophoretic force exerted on the target droplets at the electrode assembly is consistent and uniform. This improves the success rate of deflecting the target droplets and increases the throughput of the droplet sorting system.

[0256] Optionally, combined Figure 19 As shown, the electrode unit includes a positive electrode and two negative electrodes, and the positive electrodes and negative electrodes of the electrode assembly are alternately arranged.

[0257] As an implementation method, each electrode unit includes one positive electrode and two negative electrodes. Two adjacent electrode units share a common 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 multiple positive and negative electrodes in the electrode assembly are relatively uniform, and adjacent electric fields are less likely to overlap.

[0258] Optionally, the negative electrodes 820 of the electrode assemblies are connected, and the positive electrodes 810 of the electrode assemblies are independently controlled to be conductive.

[0259] The potential difference between the positive and negative electrodes creates an electric field that acts on the target droplet. Multiple negative electrodes are connected, and by supplying power to the positive electrodes, an electric field is formed between the positive and negative electrodes. This simplifies the wiring of the multiple negative electrodes. Furthermore, the potentials of the multiple negative electrodes are equal when connected, making it easier to adjust the electric field strength by adjusting the voltage of the positive electrodes.

[0260] Multiple positive electrodes are independently controlled to conduct electricity, and multiple positive electrodes can be energized simultaneously or one by one. This arrangement facilitates the electrode assembly to achieve a variety of different sorting methods.

[0261] Optionally, combined Figure 19 As shown, the electrode assembly further includes a first shielding electrode 870 , which is disposed on the second side of the liquid droplet channel 311 , and is opposite to the electrode unit.

[0262] A first shielding electrode is provided, and the electromagnetic effect generated by the positive electrode on the second side of the first flow channel is confined within the first shielding electrode. This can reduce the electromagnetic interference caused by the electric field between the positive electrode and the negative electrode to the electronic components of the droplet sorting system.

[0263] Optionally, the first shielding electrode 870 is connected to the negative electrode 820 of the electrode unit.

[0264] In this case, the negative electrode of the electrode unit is a ground electrode, and the first shielding electrode is also a ground electrode. This can simplify the wiring of the negative electrode and the first shielding electrode of the electrode assembly, thereby reducing the cost of the electrode assembly.

[0265] Optionally, combined Figure 19 、 Figure 20 As shown, the electrode assembly further includes a second shielding electrode 880 , which is disposed on the first side of the droplet flow channel. The second shielding electrode is disposed on the circumferential outside of the electrode unit and surrounds the electrode unit.

[0266] A second shielding electrode is provided, and the electromagnetic effect generated by the positive electrode on the first side of the first flow channel is confined within the second shielding electrode. This can further reduce the electromagnetic interference caused by the electric field between the positive electrode and the negative electrode on the electronic components of the droplet sorting system.

[0267] Optionally, the second shielding electrode 880 is connected to the negative electrode 820 of the electrode unit.

[0268] In this case, the negative electrode of the electrode unit is the ground electrode, and the second shielding electrode is also the ground electrode. This can simplify the wiring of the negative electrode and the second shielding electrode of the electrode assembly, thereby reducing the cost of the electrode assembly.

[0269] The electrode assembly provided in the embodiment of the present disclosure can provide continuous and uniform pulling force for the target droplets, thereby allowing the droplets to pass through the droplet flow channel at a higher speed, which can significantly improve the droplet sorting flux; by providing pulling force for the target droplets through multiple electrode units or multiple positive electrodes of the electrode assembly, the pulling force on the target droplets is relatively gentle, and the droplets are not easily broken.

[0270] Optionally, the positive electrode and / or the negative electrode of the electrode unit is connected to a power source via a high-voltage isolation pulse transformer.

[0271] The high-voltage isolation pulse transformer provides high electrical isolation between the primary and secondary sides, ensuring the safety of equipment and personnel. The transformer can transmit pulse signals and exhibits excellent pulse response characteristics. This configuration improves the safety of the droplet sorting system.

[0272] If multiple positive electrodes are energized, target droplets are subject to multiple electric fields as they flow through the electrode assembly. This creates a complex force on the target droplets and makes them susceptible to breakage. By controlling the multiple positive electrodes to energize them one by one, the target droplets are subject to only one or two electric fields at a time. This makes the deflection of the target droplets easier to control and less likely to break.

[0273] Optionally, combined Figures 16 to 21 As shown, the flow channel assembly includes a microfluidic chip, and the microfluidic chip defines a droplet flow channel 311, a first liquid outlet flow channel 314 and a second liquid outlet flow channel 315 inside the microfluidic chip.

[0274] The microfluidic chip 310 enables high-throughput droplet sorting, thereby improving the efficiency of experimental research. Microfluidic chips are low-cost, easy to use, and portable, reducing experimental costs. Microfluidic chip technology also enables non-destructive droplet sorting, ensuring sample activity and integrity.

[0275] Optionally, the microfluidic chip further defines a sheath liquid inflow channel 312 and a sample liquid inflow channel 313, wherein the liquid inlet end of the sample liquid inflow channel 313 is used to fill droplets that have passed through a pre-magnetized magnetic field, and the liquid outlet end of the sample liquid inflow channel 313 and the liquid outlet end of the sheath liquid inflow channel 312 are connected to the liquid inlet end of the droplet channel 311, and the droplets that have passed through the pre-magnetized magnetic field are mixed with the sheath liquid and then enter the droplet channel 311.

[0276] The pre-magnetized droplets are water-in-oil droplets surrounded by sheath fluid. This oil-in-water droplet structure is intended to isolate antibodies and antigens from interfering with each other between adjacent droplets. After entering the sample liquid inflow channel 313 of the microfluidic chip 310, these water-in-oil droplets remix with the sheath liquid in the sheath liquid inflow channel 312, allowing the droplets to flow within the droplet flow channel 311 at a predetermined flow rate and within a predetermined distance. This arrangement facilitates the identification, observation, and sorting of samples contained within the droplets within the microfluidic chip 310.

[0277] Optionally, the microfluidic chip further defines a positive electrode flow channel and a negative electrode flow channel 317 , the positive electrode flow channel and the negative electrode flow channel 317 are filled with a conductive medium to form a positive electrode, and / or the negative electrode flow channel 317 is filled with a conductive medium to form a negative electrode.

[0278] With this configuration, the positive electrode 810 and the negative electrode 820 of the microfluidic chip 310 are located inside the microfluidic chip 310, which can better drive the droplets to deflect within the plane of the microfluidic chip 310. Furthermore, the positive electrode 810 and the negative electrode 820 are embedded in the microfluidic chip 310, reducing the risk of electrode short circuits or leakage in the droplet sorting system.

[0279] Optionally, the conductive medium is made of metal, and the metal conductive medium is filled into the positive electrode flow channel and / or the negative electrode flow channel in liquid form.

[0280] Adopting such a configuration reduces the difficulty of processing and forming the positive electrode and the negative electrode, and reduces the cost of the droplet sorting system.

[0281] Optionally, the positive electrode flow channel is located on one side of the liquid droplet flow channel 311 , and the negative electrode flow channel 317 is located on the other side of the liquid droplet flow channel 311 .

[0282] The positive electrode flow channel and the negative electrode flow channel 317 are both located in the plane of the microfluidic chip and on either side of the droplet flow channel 311. The target droplets are deflected in the same plane by the electrophoretic force. This arrangement facilitates the deflection of the target droplets under the action of the electrophoretic force.

[0283] Optionally, the conductive medium is made of metal, and the metal conductive medium is filled into the positive electrode flow channel 316 in liquid form.

[0284] This configuration reduces the difficulty of forming the metal electrode and reduces the cost of the droplet sorting system.

[0285] Optionally, when the electrode assembly further includes a first shielding electrode, the microfluidic control chip further defines a first shielding electrode flow channel 318, the first shielding electrode flow channel is filled with a conductive medium to form the first shielding electrode, and the negative electrode flow channel is also connected to the first shielding electrode flow channel.

[0286] In this way, the first shielding electrode can be integrated into the microfluidic chip, which simplifies the structure of the sorting device and reduces the cost of the sorting device.

[0287] Optionally, when the electrode assembly further includes a second shielding electrode, the microfluidic control chip further defines a second shielding electrode flow channel 319, which is filled with a conductive medium to form a second shielding electrode, and the negative electrode flow channel is also connected to the second shielding electrode flow channel.

[0288] In this way, the second shielding electrodes can be integrated into the microfluidic chip, which simplifies the structure of the sorting device and reduces the cost of the sorting device.

[0289] Optionally, combined Figure 21 As shown, the microfluidic control chip also defines a connecting channel 3189, a first end of the connecting channel 3189 is connected to the first shielding electrode channel 318, a second end of the connecting channel is connected to the second shielding electrode channel 319, the second shielding electrode channel is directly connected to the negative electrode channel, and the first shielding electrode channel is connected to the negative electrode channel through the connecting channel.

[0290] With this arrangement, multiple negative electrodes, first shielding electrodes, and second shielding electrodes can be connected through only one electrode connector, which simplifies the connection structure of the negative electrodes, first shielding electrodes, and second shielding electrodes and reduces the cost of the sorting device.

[0291] Optionally, combined Figure 15 As shown, the sorting device also includes an electrode mounting plate 840, a positive electrode connector 831, and a negative electrode connector 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 connector 831 is fixed to the electrode mounting plate 840 and extends to the positive electrode flow channel 316 of the microfluidic chip. The negative electrode connector 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 connector 831 is used to conductively connect the positive electrode to a power source, and the negative electrode connector is used to conductively connect the negative electrode to a power source.

[0292] With this arrangement, the positive and negative electrodes of the electrode assembly can be easily connected to or disconnected from the power supply. In addition, the connection is tight through the electrode connector, and the positive and negative electrodes are not prone to malfunction due to a loose connection.

[0293] Combine Figure 22 As shown, the embodiment of the present disclosure provides a fluorescence signal detection method for enhancing the fluorescence signal of a droplet, the method comprising:

[0294] S01, a fluorescence signal detection device pre-magnetizes the droplet to aggregate the magnetic particles in the droplet.

[0295] S02, the fluorescence signal detection device applies a magnetic field to the droplet to pull the agglomerated magnetic particles into a line shape.

[0296] S03, the fluorescence signal detection device applies laser light to the linear magnetic particles to make the fluorescent markers bound to the magnetic particles in the droplets emit light.

[0297] S04, a fluorescent signal detection device detects the fluorescent signal of the fluorescent marker in the droplet.

[0298] The fluorescence detection method provided by the embodiments of the present disclosure can be used to identify samples such as cells, bacteria, and viruses. The droplet includes at least one cell, bacteria, or virus, and a fluorescently identifiable marker.

[0299] As a usage mode, the fluorescence signal enhancement method provided by the embodiment of the present disclosure is applied to the following sample liquid: the sample liquid includes multiple droplets, the droplets include at least one cell, multiple magnetic particles, multiple antibodies that specifically bind to the magnetic particles, multiple antigens and / or secondary antibodies that specifically bind to the antibodies, and at least one of the antigens and / or secondary antibodies is fluorescently stained.

[0300] In the disclosed embodiments, pre-magnetizing the droplets to aggregate the magnetic particles in the droplets can be performed using the pre-magnetization component of the fluorescence signal enhancement device described in the above embodiments, or by applying a magnetic field to the droplets after incubation to magnetize and aggregate the magnetic particles. Since the incubation has already concluded, the magnetization of the magnetic particles does not affect the incubation effect.

[0301] In the disclosed embodiments, applying a magnetic field to droplets can be accomplished in the aforementioned chip assembly or in other flow cytometry sorting devices. In any sorting method, pulling the magnetic particle clusters into a linear shape can improve the accuracy of fluorescent identification of droplets.

[0302] The fluorescence signal detection method provided in the embodiments of the present disclosure can be implemented based on the above-mentioned fluorescence signal enhancement device, fluorescence signal detection device or droplet observation device.

[0303] After pre-magnetizing the droplets, the magnetic particles in the droplets are magnetized and aggregated. The aggregated magnetic particles are pulled into a linear shape in the first magnetic field. Because the magnetic particles are linear, the antigens and / or secondary antibodies bound to them are also distributed linearly. Applying laser light to the linear magnetic particles allows for more complete excitation of the antigens and / or secondary antibodies. When detecting the fluorescent signal of the fluorescent marker, the signal exhibits distinct characteristic peaks. This characteristic peak of the antigens and / or secondary antibodies allows for a more accurate determination of the presence of target cells in the droplet.

[0304] Using the droplet sorting method provided in the embodiment of the present disclosure, the magnetic particles can be magnetized by the pre-magnetization component before entering the first magnetic field to form a clustered state. After entering the magnetic field, the magnetized and clustered magnetic particles can be better pulled into a linear shape, so that the fluorescent substance in the particle cluster can be more fully excited by the laser, thereby improving the recognition accuracy of the droplets.

[0305] Optionally, pre-magnetizing the droplets to aggregate the magnetic particles in the droplets includes: applying a pre-magnetization magnetic field to the magnetic particles to magnetize the magnetic particles in the droplets; and changing the direction and / or intensity of the pre-magnetization magnetic field multiple times to promote the aggregation of the magnetized magnetic particles in the droplets.

[0306] Magnetic particles in liquid droplets are not only magnetized in the pre-magnetization magnetic field but also rotate and move under the influence of the magnetic force, causing them to agglomerate. While the magnetic particles can be magnetized in a relatively short time, agglomeration takes longer. Changing the direction of the pre-magnetization magnetic field intensifies the movement of the magnetic particles in the field, accelerating their agglomeration. This method can enhance the agglomeration of magnetic particles in liquid droplets in the pre-magnetization magnetic field.

[0307] Optionally, changing the direction of the pre-magnetization magnetic field multiple times includes: controlling the direction of the pre-magnetization magnetic field to change over time; or changing the angle of the droplet in the pre-magnetization magnetic field multiple times.

[0308] In one implementation, the pre-magnetized magnet includes an AC electromagnet. When energized, the pre-magnetized magnet generates a circumferential magnetic field. In another implementation, the droplets form a directional flow path as they flow within the pre-magnetized magnetic field. This facilitates the movement of magnetic particles within the droplets within the pre-magnetized magnetic field, leading to agglomeration.

[0309] Optionally, changing the intensity of the pre-magnetization magnetic field multiple times includes: controlling the intensity of the pre-magnetization magnetic field to change over time; or changing the position of the droplet in the pre-magnetization magnetic field multiple times.

[0310] In one implementation, the pre-magnetized magnet includes an electromagnet, and the strength of the pre-magnetized magnetic field is varied by changing the current intensity of the electromagnet. In another implementation, as the droplets flow within the pre-magnetized magnetic field, they are positioned at different locations within the pre-magnetized magnetic field, thereby varying the magnetic field strength acting on the droplets. This facilitates the movement of magnetic particles within the droplets within the pre-magnetized magnetic field, leading to agglomeration.

[0311] Combine Figure 23 As shown, the embodiment of the present disclosure provides a droplet sorting method, the method comprising:

[0312] S11, the droplet sorting system pre-magnetizes the droplets to agglomerate the magnetic particles in the droplets.

[0313] S21, the droplet sorting system applies a magnetic field to the droplets to pull the agglomerated magnetic particles into a wire shape.

[0314] S31, the droplet sorting system applies laser light to the linear magnetic particles to make the fluorescent markers bound to the magnetic particles in the droplets emit light.

[0315] S41, the droplet sorting system marks the droplets that meet the fluorescence conditions as target droplets.

[0316] S51, the droplet sorting system applies a deflection force to the target droplet to deflect the target droplet end to the target flow channel.

[0317] The fluorescence detection method provided by the embodiments of the present disclosure can be used to identify samples such as cells, bacteria, and viruses. The droplet includes at least one cell, bacteria, or virus, and a fluorescently identifiable marker.

[0318] Illustratively, the droplet sorting method provided in the embodiments of the present disclosure is used to sort cells prepared as oil-in-water droplets, wherein the droplets include 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, and at least one of the antigens and / or secondary antibodies is fluorescently stained.

[0319] In the disclosed embodiments, pre-magnetizing the droplets to aggregate the magnetic particles in the droplets can be performed using the pre-magnetization component of the fluorescence signal enhancement device described in the above embodiments, or by applying a magnetic field to the droplets after incubation to magnetize and aggregate the magnetic particles. Since the incubation has already concluded, the magnetization of the magnetic particles does not affect the incubation effect.

[0320] In the disclosed embodiments, applying a magnetic field to the droplets can be accomplished in the aforementioned chip assembly or in other flow cytometry devices. The magnetic particle clusters are drawn into a linear shape, which can improve the accuracy of fluorescent cell identification.

[0321] Using the droplet sorting method provided in the embodiment of the present disclosure, the magnetic particles can be magnetized by the pre-magnetization component before entering the first magnetic field to form a clustered state. After entering the magnetic field, the magnetized and clustered magnetic particles can be better pulled into a linear shape, so that the fluorescent substance in the particle cluster can be more fully excited by the laser, thereby improving the recognition accuracy of the droplets.

[0322] Optionally, applying a deflection force to the target droplet to deflect the target droplet end to the target flow channel includes: the droplet sorting system sequentially activates multiple electrodes arranged along the droplet flow direction to apply electrophoretic force to the target droplet multiple times to deflect the target droplet to the target flow channel.

[0323] The sorting device includes a positive electrode and a negative electrode. Multiple positive electrodes are spaced apart and arranged on one side of the droplet flow path. When the multiple positive electrodes are activated sequentially, they apply deflection forces to target droplets, thereby deflecting the target droplets toward the target flow path, which is also the first outlet flow path mentioned above.

[0324] With this arrangement, the electrophoretic force acts on the droplet for a longer time, which can better deflect the droplet to the target flow channel.

[0325] Optionally, the target flow channel is connected to a first air pump, and applying a deflection force to the target droplet to deflect the target droplet end to the target flow channel includes: starting the first air pump to apply positive pressure to the target flow channel when the non-target droplet pre-enters the target flow channel to deflect the non-target droplet to the non-target flow channel.

[0326] When the first air pump is operating, it applies positive pressure to the first outlet channel. This creates a pressure differential between the first and second outlet channels. As non-target droplets flow through the outlet section of the droplet channel, they are deflected toward the second outlet channel due to the pressure differential. The air pump's rapid response speed enables high-speed droplet sorting. Furthermore, when the air pump applies positive pressure to the first outlet channel, the force is evenly distributed across the droplets, minimizing damage to the sample within them.

[0327] Optionally, the non-target flow channel is connected to a second air pump, and applying a deflection force to the target droplet to deflect the target droplet end to the target flow channel includes: starting the second air pump to apply positive pressure to the non-target flow channel when the target droplet pre-enters the non-target flow channel to deflect the target droplet to the target flow channel.

[0328] When the second air pump is operating, it applies positive pressure to the second outlet channel. This creates a pressure differential between the first and second outlet channels. As target droplets flow through the outlet section of the droplet channel, they are deflected toward the first outlet channel by this pressure differential. This allows for high-speed droplet sorting and minimizes damage to the sample within the target droplet during deflection.

[0329] Optionally, the droplets contain multiple antibodies that specifically bind to magnetic particles, multiple antigens that specifically bind to antibodies, and multiple secondary antibodies that specifically bind to antibodies, and the antigens and secondary antibodies are all fluorescently stained; wherein the droplet sorting system applies a laser to the linear magnetic particles to cause the fluorescent markers bound to the magnetic particles in the droplets to emit light, including: applying a first laser and a second laser to the linear magnetic particles to cause the first fluorescent marker and the second fluorescent marker bound to the magnetic particles in the droplets to emit light; marking droplets that meet the fluorescence conditions as target droplets, including: marking droplets whose first fluorescent signal meets the first condition and whose second fluorescent signal meets the second condition as target droplets.

[0330] After applying the first and second lasers to the droplet, the antibodies and antigens in the droplet are excited to emit first and second fluorescent signals. If the intensities of both the first and second fluorescent signals meet preset conditions, the droplet is deemed to contain a cluster of particles consisting of magnetic particles, antibodies, antigens, and secondary antibodies, and the droplet is marked as a target droplet.

[0331] By adopting such a setting, the accuracy of droplet recognition can be further improved.

[0332] Optionally, the second condition is determined based on the first condition.

[0333] The number of magnetic particle antigens and secondary antibodies in different droplets varies. When there are fewer magnetic particles or antigens in the particle cluster, it is assumed that there are fewer antibodies. Therefore, when the first fluorescence signal is weak, setting a correspondingly lower second condition for the second fluorescence signal helps identify more target droplets that meet the application requirements.

[0334] Optionally, combined Figure 24 As shown, after marking the droplets whose first fluorescent signals meet the first condition and whose second fluorescent signals meet the second condition as target droplets, the droplet sorting method further includes:

[0335] S61, the droplet sorting system obtains the first moment when the target droplet flows through the imaging position.

[0336] S71, the droplet sorting system starts the imaging component at the first moment to acquire an image of the target droplet.

[0337] With this setting, images of target droplets can also be obtained during the droplet sorting process, which not only helps users analyze and study the target droplets based on the images of the target droplets, but also makes it easy for users to adjust parameters such as the pre-magnetization magnetic field strength, first magnetic field strength, and droplet flow rate of the droplet sorting system based on the obtained images.

[0338] Optionally, combined Figure 24 As shown, after calculating the first moment when the target droplet flows through the imaging position, the droplet sorting method further includes:

[0339] S81, the droplet sorting system starts the light source component at the first moment to provide supplementary light for the imaging component.

[0340] The light source assembly is only started at the first moment, which can reduce light pollution of the light source assembly and increase the service life of the light source assembly.

[0341] Combine Figure 25As shown, an embodiment of the present disclosure provides a fluorescence signal detection device, including a processor 900 and a memory 901. Optionally, the device may also include a communication interface 902 and a bus 903. The processor 900, the communication interface 902, and the memory 901 may communicate with each other via the bus 903. The communication interface may be used for information transmission. The processor may call logic instructions in the memory to execute the fluorescence signal detection method of the above embodiment.

[0342] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0343] Memory, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. The processor executes the program instructions / modules stored in the memory to perform functional applications and data processing, thereby implementing the droplet sorting methods in the above-described embodiments.

[0344] The memory may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Furthermore, the memory may include high-speed random access memory and non-volatile memory.

[0345] Combine Figures 1 to 21 As shown, an embodiment of the present disclosure provides a droplet sorting system, comprising: a droplet sorting system body, and the above-mentioned fluorescent signal detection device. The fluorescent signal detection device is installed on the product body. The installation relationship described here is not limited to placement inside the product, but also includes installation connections with other components of the product, including but not limited to physical connections, electrical connections or signal transmission connections, etc. It can be understood by those skilled in the art that droplets can be adapted to a feasible product body, thereby realizing other feasible embodiments.

[0346] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the above-mentioned fluorescence signal detection method.

[0347] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0348] The technical solution of the embodiments of the present disclosure may be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may 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 may be a non-transitory storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program code, or a transient storage medium.

[0349] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include plural forms. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups of these. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be found in the description of the method part.

[0350] Those skilled in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. The technicians will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0351] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units can be merely a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, and can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. In addition, the functional units in the embodiments of the present disclosure may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0352] The flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the systems, methods and computer program products according to the embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment or part of the code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical functions. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, 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, or they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A fluorescence signal enhancement device for enhancing the fluorescence signal of a droplet, characterized in that: include: A pre-magnetization component is used to generate a pre-magnetization magnetic field, in which the magnetic particles in the droplets are magnetized and agglomerated; The magnet assembly is used to generate a first magnetic field, and the magnetic particles agglomerated in the droplets are pulled into a line shape in the first magnetic field.

2. The fluorescence signal enhancement device according to claim 1, characterized in that: The magnetic field strength of the pre-magnetization magnetic field is greater than the magnetic field strength of the first magnetic field.

3. The fluorescence signal enhancement device according to claim 1, characterized in that: The pre-magnetization component comprises: a pre-magnetized pipeline defining a pre-magnetized flow channel for the flow of droplets; The pre-magnetized magnet is used to generate a pre-magnetized magnetic field, and at least a portion of the pre-magnetized flow channel is located in the pre-magnetized magnetic field.

4. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetized magnet comprises: The pre-magnetization coil is wound around the pre-magnetization pipeline, and the axis of the pre-magnetization coil is along the length direction of the pre-magnetization pipeline. When the coil is energized, the pre-magnetization magnetic field is generated.

5. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetized magnet comprises: a first pre-magnetization magnet, disposed on one side of the pre-magnetization pipeline; The second pre-magnetization magnet is arranged on the other side of the pre-magnetization pipeline.

6. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetized magnet is used to generate a pre-magnetized magnetic field with a changing direction. When the magnetic particles in the droplet are in the pre-magnetized flow channel, they are moved and agglomerated by the changing magnetic field force.

7. The fluorescence signal enhancement device according to claim 6, characterized in that: The pre-magnetized magnet includes a plurality of magnet pairs, which are arranged close to the pre-magnetized flow channel. Magnetic flux lines are formed between each magnet pair, and the directions of the magnetic flux lines of the plurality of magnet pairs are different to form the pre-magnetized magnetic field with changing direction.

8. The fluorescence signal enhancement device according to claim 6, characterized in that: The pre-magnetized magnet includes an electromagnet, and the pre-magnetized magnetic field with the changing direction is formed by adjusting the current intensity and / or current direction of the electromagnet; or The pre-magnetization magnet includes a coil, which is wound around the pre-magnetization pipeline. When the coil is energized, the pre-magnetization magnetic field is generated. The pre-magnetization magnetic field with changing direction is formed by adjusting the current intensity and / or current direction of the coil.

9. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetized flow channel is a flow channel with a changing direction. At least a portion of the flow channel with a changing direction is located in the pre-magnetized magnetic field. When the magnetic particles in the droplets move in the flow channel with a changing direction, they are moved and agglomerated by the force of the first magnetic field.

10. The fluorescence signal enhancement device according to claim 9, characterized in that: The pre-magnetized flow channel includes a plurality of bent sections, which are connected end to end to form a pre-magnetized flow channel with a changing direction.

11. The fluorescence signal enhancement device according to claim 10, characterized in that: The pre-magnetized flow channel is a spiral flow channel.

12. The fluorescence signal enhancement device according to claim 11, characterized in that: The pre-magnetized pipeline is wound around the pre-magnetized magnet to form the flow channel with changing direction.

13. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetization magnetic field includes 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 with time.

14. The fluorescence signal enhancement device according to claim 13, characterized in that: The pre-magnetization magnet includes an AC electromagnet, which forms the second part of the pre-magnetization magnetic field when energized.

15. The fluorescence signal enhancement device according to claim 13, characterized in that: The pre-magnetization magnet includes a DC electromagnet, which forms the first part of the pre-magnetization magnetic field when energized.

16. The fluorescence signal enhancement device according to claim 3, characterized in that: The pre-magnetization pipeline is a flexible hose, and the length of the portion located in the pre-magnetization magnetic field is adjusted by moving the pre-magnetization pipeline.

17. The fluorescence signal enhancement device according to any one of claims 3 to 12 and 16, characterized in that: Also includes: The flow channel component defines a droplet flow channel, at least a portion of which is located in the first magnetic field.

18. The fluorescence signal enhancement device according to claim 17, characterized in that: The pre-magnetized flow channel is connected to the droplet flow channel, and the droplet flow channel is located at the rear stage of the pre-magnetized flow channel along the droplet flow direction.

19. The fluorescence signal enhancement device according to claim 17, characterized in that: The magnet assembly comprises: A first magnet is disposed on one side of the liquid droplet flow channel; a second magnet, disposed on the other side of the liquid droplet flow channel; The length direction of the liquid droplet flow channel is along the direction of cutting the magnetic flux lines between the first magnet and the second magnet.

20. The fluorescence signal enhancement device according to claim 17, characterized in that: The flow channel assembly includes: A microfluidic chip defines a chip flow channel for droplet flow, the chip flow channel including a sheath liquid inlet channel, a sample liquid inlet channel, and a droplet flow channel. At least a portion of the droplet flow channel is located in the first magnetic field. The liquid inlet end of the sample liquid inlet channel is used to fill the droplets that have passed through the pre-magnetized magnetic field. The liquid outlet end of the sample liquid inlet channel and the liquid outlet end of the sheath liquid inlet channel are connected to the liquid inlet end of the droplet flow channel. The droplets that have passed through the pre-magnetized magnetic field mix with the sheath liquid and then enter the droplet flow channel.

21. The fluorescence signal enhancement device according to claim 20, characterized in that: The flow channel assembly further includes: The support frame includes a bottom plate, a first side plate and a second side plate, wherein the first side plate and the second side plate are arranged opposite to each other; The microfluidic chip is located between the first side plate and the second side plate, and overlapped on the upward side of the bottom plate.

22. The fluorescence signal enhancement device according to claim 21, characterized in that: Also includes: The bearing plate is provided with an installation window; A fixing assembly is used to fix the flow channel assembly to the installation window.

23. The fluorescence signal enhancement device according to claim 22, characterized in that: The fixing assembly includes: a first clamping member for fixing a first end of the chip assembly; The second clamping member is used to fix the second end of the chip assembly.

24. The fluorescence signal enhancement device according to claim 23, characterized in that: The pre-magnetization component is fixed to the supporting plate.

25. The fluorescence signal enhancement device according to claim 21, characterized in that: The magnet assembly comprises: a first magnet, disposed on an inward side of the first side plate; The second magnet is arranged on the inward side of the second side plate.

26. A fluorescence signal detection device, characterized in that: include: The fluorescence signal enhancing device according to any one of claims 1 to 25; and, A laser assembly is used to emit laser light to the magnetic particles drawn into a linear shape, and the fluorescent markers in the droplets are excited by the laser light to emit fluorescence; The fluorescence detection component is used to detect the fluorescence emitted by the fluorescent marker in the droplet.

27. The fluorescence signal detection device according to claim 26, characterized in that: In the case where claim 26 refers to any one of claims 22 to 24, The laser assembly is disposed below the carrier plate, and emits light toward the portion of the droplet flow channel located in the first magnetic field; and / or, The fluorescence detection component is disposed below the supporting plate, and its detection direction is toward the portion of the liquid droplet flow channel located in the first magnetic field.

28. The fluorescence signal detection device according to claim 27, characterized in that: An observation window is provided on the bottom plate of the support frame, and at least a first portion of the microfluidic chip corresponding to the observation window is made of a transparent material; Wherein, the light emitting direction of the laser component is toward the observation window; and / or the detection position of the fluorescence detection component corresponds to the observation window.

29. A liquid droplet observation device, characterized in that: A fluorescence signal enhancing device comprising any one of claims 1 to 25; and, a light source assembly configured to emit light toward the liquid droplets in the first magnetic field; The imaging component has an imaging position facing the liquid drop in the first magnetic field.

30. The liquid droplet observation device according to claim 29, characterized in that: In the case where claim 29 refers to any one of claims 22 to 24, The light source assembly is disposed above the carrier plate, and emits light toward the portion of the liquid droplet flow channel located in the first magnetic field; and / or, The imaging component is disposed below the carrying plate, and emits light in a direction toward the portion of the liquid droplet flow channel located in the first magnetic field.

31. The liquid droplet observation device according to claim 29, characterized in that The imaging assembly comprises: The light source assembly is opened synchronously with the shutter of the high-speed camera.

32. The liquid droplet observation device according to claim 29, characterized in that An observation window is provided on the bottom plate of the support frame, at least a first portion of the microfluidic chip corresponding to the observation window is made of a transparent material, and the imaging position of the imaging component faces the first portion of the observation window.

33. The liquid droplet observation device according to claim 32, characterized in that: At least a second portion of the upward side of the microfluidic chip corresponding to the observation window is made of a transparent material, and the light emitted by the light source assembly is directed toward the second portion of the microfluidic chip.

Images