Fluorescent signal enhancement device, fluorescent signal detection device, droplet observation device, fluorescent signal detection method

Abstract

The application 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 gathered in the pre-magnetization magnetic field; the magnet assembly is used for generating a first magnetic field, and the gathered magnetic particles in the liquid drops are pulled into a linear shape in the first magnetic field. The application further discloses a fluorescence signal detection device, a liquid drop observation device and a fluorescence signal detection method.

Description

Technical Field

[0001] This application relates to the field of cell sorting technology, such as a fluorescence signal enhancement device, a fluorescence signal detection device, a droplet observation device, and a fluorescence signal detection method. Background Technology

[0002] Antibodies are one of the important humoral immune mechanisms that protect the body from pathogens such as viruses and bacteria. Protective vaccines are crucial weapons in curbing the spread of various pathogens; they not only specifically recognize pathogens but also bind closely to antigens, effectively blocking damage to cells, tissues, and the body. Antibodies are produced by B cells and undergo a rigorous selection process within the lymphatic system, with only a very small number of B cells rearranging their genes to produce high-affinity antibodies. Effectively isolating and enriching B cells that secrete high-affinity antibodies remains a challenge in antibody research.

[0003] A system for detecting, sorting, and distributing droplets for bioassays is disclosed in related technologies. The system includes: a microfluidic device comprising a first channel connected to a second channel and a waste channel via a first sorting connector; a plurality of water-in-oil droplets, wherein at least two of the plurality of water-in-oil droplets each comprise at least one cell, at least one particle, or at least one cell plus at least one particle; a first detector or sensor corresponding to a first detection point located upstream of the sorting connector and disposed along the first channel, wherein the first detector includes an optical detector; a second detector or sensor corresponding to a second detection point located downstream of the sorting connector and disposed along the second channel; a target droplet dispensing module comprising 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] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] When a droplet flows through the first or second detection point, magnets, magnet pairs, or magnet arrays are needed to arrange the particles within the droplet according to a certain pattern, thereby making their characteristics more prominent. The magnetic particles in the droplet are magnetized near the detection point and arranged under the influence of the magnetic field. Particles in the droplet interact with nearby particles to form lines. When the magnets in the droplet are relatively dispersed, the particles rearrange themselves into multiple thin lines in the magnetic field. When the particles in the droplet are arranged into multiple thin lines, the characteristic peaks of the fluorescence signal are not obvious during fluorescence recognition of the droplet, which affects the accuracy of cell recognition.

[0006] It should be noted that the information disclosed in the background section above 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 those skilled in the art. Summary of the Invention

[0007] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0008] This disclosure provides a fluorescence signal enhancement device, a fluorescence signal detection device, a droplet observation device, and a fluorescence signal detection method to improve the accuracy of droplet identification.

[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 in which magnetic particles in the droplet are magnetized and aggregate; and the magnet component is used to generate a first magnetic field in which the aggregated magnetic particles in the droplet are drawn into a linear shape.

[0010] In some embodiments, the magnetic field strength of the pre-magnetizing magnetic field is greater than the magnetic field strength of the first magnetic field.

[0011] In some embodiments, the premagnetization assembly includes a premagnetization conduit and a premagnetization magnet, wherein the premagnetization conduit defines a premagnetized flow channel for droplet flow; and the premagnetization magnet is used to generate a premagnetized magnetic field, at least a portion of the premagnetized flow channel being located within the premagnetized magnetic field.

[0012] In some embodiments, the pre-magnetized magnet includes a pre-magnetized coil wound around the pre-magnetized conduit, the axis of the pre-magnetized coil being along the length of the pre-magnetized conduit, and the pre-magnetized magnetic field being generated when the coil is energized.

[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 droplet move and agglomerate under the action of the changing magnetic field force when they are in the pre-magnetized channel.

[0015] In some embodiments, the pre-magnetized magnet includes multiple magnet pairs disposed close to the pre-magnetized flow channel, with magnetic field lines formed between each magnet pair, and the magnetic field lines of the multiple magnet pairs having different directions to form a pre-magnetized magnetic field with varying directions.

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

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

[0018] In some embodiments, the pre-magnetized flow channel includes multiple bends connected end to end to form a pre-magnetized flow channel with varying direction.

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

[0020] In some embodiments, the pre-magnetized conduit is wound around the pre-magnetized magnet to form the directional flow channel.

[0021] In some embodiments, the pre-magnetizing magnetic field includes a first part and a second part, wherein the magnetic field direction of the first part remains unchanged, and the magnetic field direction of the second part changes over time.

[0022] In some embodiments, the pre-magnetized magnet includes an AC electromagnet, which forms a second portion of the pre-magnetized magnetic field when energized.

[0023] In some embodiments, the pre-magnetized magnet includes a DC electromagnet, which forms a first portion of the pre-magnetized magnetic field when energized.

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

[0025] In some embodiments, the fluorescence signal enhancement device further includes a flow channel assembly defining a droplet flow channel, at least a portion of which is located within the first magnetic field.

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

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

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

[0029] In some embodiments, the flow channel assembly further includes a support frame, the support frame including a base plate, a first side plate and a second side plate, the first side plate and the second side plate being disposed 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 component, wherein the carrier plate has an installation window; and the fixing component is used to fix the flow channel component to the installation window.

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

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

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

[0034] In some embodiments, the fluorescence signal detection device includes the fluorescence signal enhancement device, the laser component, and the fluorescence detection component described above. The laser component is used to emit a laser beam toward the magnetic particles stretched into a wire shape, and the fluorescent marker in the droplet is excited by the laser to emit fluorescence. The fluorescence detection component is used to detect the fluorescence emitted by the fluorescent marker in the droplet.

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

[0036] In some embodiments, the base plate of the support frame has an observation window, and at least the first part of the microfluidic chip corresponding to the observation window is made of transparent material; wherein, the light emission direction of the laser component is towards 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 fluorescence signal enhancement device, the light source assembly, and the imaging assembly described above, wherein the light source assembly emits light in the direction of the droplet in the first magnetic field; and the imaging assembly is positioned in the direction of the droplet in the first magnetic field.

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

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

[0040] In some embodiments, the base plate of the support frame has an observation window, and the microfluidic chip is made of a transparent material at least in the first part of the observation window, with the imaging position of the imaging component facing the first part of the observation window.

[0041] In some embodiments, the upward-facing side of the microfluidic chip is at least the second portion of the observation window 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] In some embodiments, the fluorescence signal detection method includes: pre-magnetizing a droplet to cause magnetic particles in the droplet to agglomerate; applying a magnetic field to the droplet to pull the agglomerated magnetic particles into a linear shape; applying a laser to the linear magnetic particles to cause fluorescent markers bound to the magnetic particles in the droplet to emit light; and detecting the fluorescence signal of the fluorescent markers in the droplet.

[0043] In some embodiments, pre-magnetizing a droplet to cause the magnetic particles in the droplet to agglomerate includes: applying a pre-magnetizing magnetic field to the magnetic particles to magnetize the magnetic particles in the droplet; and repeatedly changing the direction and / or intensity of the pre-magnetizing magnetic field to promote the agglomeration of the magnetized magnetic particles in the droplet.

[0044] In some embodiments, repeatedly changing the direction of the pre-magnetizing magnetic field includes: controlling the direction of the pre-magnetizing magnetic field to change over time; or, repeatedly changing the angle of the droplet in the pre-magnetizing magnetic field.

[0045] In some embodiments, repeatedly changing the strength of the pre-magnetizing magnetic field includes: controlling the strength of the pre-magnetizing magnetic field to change over time; or, repeatedly changing the position of the droplet in the pre-magnetizing magnetic field.

[0046] The fluorescence signal enhancement device, fluorescence signal detection device, droplet observation device, and fluorescence signal detection method provided in this disclosure can achieve the following technical effects:

[0047] Pre-magnetizing the droplets allows the magnetic particles to be magnetized before entering the first magnetic field, thus forming an aggregated state. After entering the first magnetic field, the magnetized and aggregated magnetic particles can be better pulled into a linear shape, thereby allowing the fluorescent material in the particle cluster to be more fully excited by the laser, thereby improving the droplet recognition accuracy.

[0048] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0049] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0050] Figure 1 This is a schematic diagram of the structure of a fluorescence signal enhancement device provided in an embodiment of this disclosure;

[0051] Figure 2 This is a schematic diagram of another fluorescence signal enhancement device provided in an embodiment of this disclosure;

[0052] Figure 3 This is a schematic diagram of the structure of a droplet recognition device provided in an embodiment of this disclosure;

[0053] Figure 4 This is a schematic diagram of another droplet recognition device provided in an embodiment of this disclosure;

[0054] Figure 5 This is a microscopic image of the unmagnetized droplet;

[0055] Figure 6 This is a microscopic image of the droplet after pre-magnetization;

[0056] Figure 7 This is a microscopic image of the unmagnetized droplet in the first magnetic field.

[0057] Figure 8 This is a microscopic image of the pre-magnetized droplet in the first magnetic field.

[0058] Figure 9 This is a fluorescence signal intensity diagram of a droplet in the first magnetic field, where the left part is the fluorescence signal intensity without pre-magnetization of the droplet, and the right part is the fluorescence signal intensity after pre-magnetization of the droplet;

[0059] Figure 10 This is a schematic diagram of the structure of a microchannel chip for a fluorescence signal enhancement device provided in an embodiment of this disclosure;

[0060] Figure 11 This is a schematic diagram of the structure of a microchannel chip for another fluorescence signal enhancement device provided in this embodiment;

[0061] Figure 12 This is a schematic diagram of the structure of a fluorescence signal detection device provided in an embodiment of this disclosure;

[0062] Figure 13 This is a schematic diagram of the structure of a droplet observation device provided in an embodiment of this disclosure;

[0063] Figure 14 This is a schematic diagram of another droplet observation device provided in an embodiment of this disclosure;

[0064] Figure 15 yes Figure 14 Enlarged view of point A in the middle;

[0065] Figure 16 This is a schematic diagram of the structure of an electrode assembly provided in an embodiment of this disclosure;

[0066] Figure 17 This is a schematic diagram of another electrode assembly provided in an embodiment of this disclosure;

[0067] Figure 18 This is a schematic diagram of another electrode assembly provided in an embodiment of this disclosure;

[0068] Figure 19 This is a schematic diagram of another electrode assembly provided in an embodiment of this disclosure;

[0069] Figure 20 This is a schematic diagram of another electrode assembly provided in an embodiment of this disclosure;

[0070] Figure 21 This is a schematic diagram of another electrode assembly provided in an embodiment of this disclosure;

[0071] Figure 22 This is a schematic diagram of a fluorescence signal detection method provided in an embodiment of this disclosure;

[0072] Figure 23 This is a schematic diagram of a droplet sorting method provided in an embodiment of this disclosure;

[0073] Figure 24 This is a schematic diagram of another droplet sorting method provided in an embodiment of this disclosure;

[0074] Figure 25 This is a schematic diagram of a fluorescence signal detection device provided in an embodiment of this disclosure.

[0075] Figure label:

[0076] 100: Pre-magnetized component; 110: Pre-magnetized conduit; 120: Pre-magnetized magnet; 121: First pre-magnetized magnet; 122: Second pre-magnetized magnet; 123: Pre-magnetized coil; 200: Magnet assembly; 210: First magnet; 220: Second magnet; 300: Chip assembly; 310: Microfluidic chip; 311: Droplet channel; 312: Sheath fluid inflow channel; 3121: Sheath fluid injection port; 313: Sample fluid inflow channel; 3131: Sample fluid injection port; 314: First outlet channel; 3141: First outlet; 315: Second outlet channel; 3151: Second outlet; 316: Positive electrode channel; 317: Negative electrode channel; 320: Support frame; 322: First side plate; 323: Second... Two side plates; 410: First laser source; 420: Second laser source; 430: Coaxial system; 500: Fluorescence detection component; 510: First photomultiplier tube; 520: Second photomultiplier tube; 610: High-speed camera; 620: Light source assembly; 710: Support plate; 720: Fixing component; 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 Implementation

[0077] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0078] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0079] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0080] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0081] Unless otherwise stated, the term "multiple" means two or more.

[0082] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0083] 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.

[0084] The term "magnetic particles" can be used interchangeably with "magnetic beads," where "magnetic particles" or "magnetic beads" refer to paramagnetic particles that can specifically bind to antigens, antibodies, or secondary antibodies.

[0085] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0086] Antibodies are one of the important humoral immune mechanisms that protect the body from pathogens such as viruses and bacteria. Protective vaccines are crucial weapons in curbing the spread of various pathogens; they not only specifically recognize pathogens but also bind closely to antigens, effectively blocking damage to cells, tissues, and the body. Antibodies are produced by B cells and undergo a rigorous selection process within the lymphatic system, with only a very small number of B cells rearranging their genes to produce high-affinity antibodies. Effectively isolating and enriching B cells that secrete high-affinity antibodies remains a challenge in antibody research.

[0087] The related technology discloses a microfluidic chip device and its usage method based on a magnetic field-controlled sorting method for fluorescently labeled cells. 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 signals labeled on the cells, the FACS system is combined with the magnetic field-controlled sorting system to achieve automated cell sorting.

[0088] The problem with the related technology is that the distribution of fluorescent substances in the droplets is relatively dispersed during the fluorescence recognition process, which leads to the characteristic peaks of the fluorescence signal being indistinct, thus affecting the accuracy of droplet recognition.

[0089] To improve the accuracy of droplet recognition, combined with Figures 1 to 4 As shown, this 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. The pre-magnetization component 100 is used to generate a pre-magnetization magnetic field, in which magnetic particles in the droplet are magnetized and aggregated. The magnet component 200 is used to generate a first magnetic field, in which the aggregated magnetic particles in the droplet are pulled into a linear shape.

[0090] For example, the droplet sorting system provided in this disclosure can be used to sort biological samples such as cells, bacteria, and viruses. Each droplet contains at least one cell, bacterium, or virus, and a fluorescently identifiable marker.

[0091] As one of the optional implementations, the fluorescence signal enhancement device provided in this disclosure is applied to the following sample solution: the sample solution includes multiple droplets, each droplet containing at least one cell, multiple magnetic particles, multiple fluorescently labeled antigens, and fluorescently labeled secondary antibodies.

[0092] After an antigen is recognized, the cell produces a variety of antibodies, and the antigen can bind to a variety of antibodies. Magnetic particles have multiple functional groups on their surface, which can bind to a variety of antibodies secreted by the cell. Secondary antibodies bind only to specific antibodies. If a target particle cluster containing antigen, antibody, magnetic particles, and secondary antibody is found in a droplet, then the cell in that droplet is considered a target cell capable of producing high-affinity antibodies, and that droplet is considered a target droplet.

[0093] To confirm the presence of target particles within the droplet, the antigen and antibody within the target particles can be identified by fluorescence. Specifically, a first laser and / or a second laser are applied to the droplet. Fluorescent substances in the antigen emit first fluorescence upon excitation by the first laser, and fluorescent substances in the secondary antibody emit second fluorescence upon excitation by the second laser. If the intensity or characteristic peak of both the first and / or second fluorescence meets preset conditions, the droplet is considered the target droplet.

[0094] In practice, the fluorescent antigen and secondary antibody are distributed in each droplet. In some cases, even if the secondary antibody in a droplet does not bind to the antibody, the laser can still excite the unbound secondary antibody, resulting in a secondary fluorescence that interferes with the judgment. In other cases, even if the secondary antibody in a droplet binds to the antibody, the irregular distribution of the target particle clusters makes the fluorescence characteristic peaks emitted by the laser-excited antigen and secondary antibody indistinct, which can also easily lead to misjudgment.

[0095] Before or during laser excitation of the fluorescent substance, a magnetic field is applied to the droplet, causing the target particle clusters to align in a specific pattern. This reduces misidentification of the target droplet. Specifically, the magnetic particles are paramagnetic. Magnetic particles themselves are not magnetic, preventing aggregation during or before sample incubation that could affect antibody binding. Paramagnetic particles are magnetized in the magnetic field, exhibiting magnetism and distributing according to the magnetic field lines. The positions of the magnetic particles change, and the particle clusters, with magnetic particles as the key component, are distributed in the droplet according to a specific pattern. Secondary antibodies not bound to the antibody do not follow this pattern. When a laser is applied to the droplet, the target particle clusters distributed in this pattern emit fluorescence. If the first fluorescence characteristic peak in the particle cluster is prominent, the identification is considered effective. Furthermore, if the second fluorescence characteristic peak meets preset conditions, the cell is considered to secrete an antibody that specifically binds to the secondary antibody, meaning the droplet is the target droplet.

[0096] Unmagnetized magnetic particles are magnetized upon entering a magnetic field. A magnetic domain is a region within a ferromagnetic material where atomic magnetic moments (i.e., the spin magnetic moments of electrons) align uniformly, forming a localized magnetized region. Without an external magnetic field, these domains are randomly arranged within the material, resulting in a macroscopically non-magnetic appearance. When an external magnetic field is applied, the magnetic moments of these domains tend to align with the field, causing the material to exhibit magnetism. The domains rearrange themselves along the magnetic field lines, making the magnetic particles appear magnetic macroscopically. If the direction of the magnetic field lines changes significantly with the droplet's flow, the magnetization effect on the magnetic particles is poor. If the change is small, the initial position of the magnetic field particles is more likely to be their magnetized position within the field. In other words, unmagnetized magnetic particles entering a magnetic field are less likely to follow a specific pattern or a straight line / curve, affecting cell recognition results.

[0097] In order to make the magnetic particles more regularly distributed in the magnetic field, the fluorescence signal enhancement device provided in this disclosure includes a pre-magnetization component 100.

[0098] The pre-magnetizing component 100 is used to make the magnetic particles exhibit magnetism macroscopically, that is, to display N poles and S poles. Specifically, the pre-magnetizing component 100 is used to generate a pre-magnetic magnetic field, in which the magnetic particles rearrange themselves according to the direction of the magnetic field lines, thereby exhibiting magnetism macroscopically. It should be noted that during and after the magnetization process, under the influence of the magnetic field force and the Brownian motion of the magnetic particles, the magnetic particles approach each other, becoming aggregated. The aggregated state can be defined as the magnetic particles inside the droplet attracting each other.

[0099] The fluorescence signal enhancement device provided in this embodiment further includes a magnet assembly 200. The magnet assembly 200 is located after the pre-magnetization assembly 100. The pre-magnetized magnetic particles enter the first magnetic field formed by the magnet assembly 200 along with the droplet. Since the magnetic particles are in a magnetized state, they are not easily remagnetized by the first magnetic field, but tend to rotate or move in the first magnetic field so that the magnetic field lines inside the magnetic particles tend to be in the same direction as the magnetic field lines of the first magnetic field. In this case, when the magnetic field lines in the first magnetic field are straight, multiple magnetic particles are distributed along a straight line; when the magnetic field lines in the first magnetic field are curved, multiple magnetic particles are distributed along a curved line. In addition, the multiple magnetic particles entering the first magnetic field are in a clustered state, and under the action of the magnetic force of the first magnetic field, the clustered magnetic particles are distributed along the same or adjacent magnetic field lines in the first magnetic field. This makes the distribution of magnetic particles in the first magnetic field more regular, which helps to reduce misjudgments caused by irregular distribution of magnetic particles, thereby improving the accuracy of droplet recognition.

[0100] Combination Figure 5 As shown, the distribution of unmagnetized magnetic particles and particle clusters is relatively dispersed; combined with Figure 6 As shown, the magnetic particles and particle clusters after pre-magnetization are distributed in an agglomerated state.

[0101] Combination Figure 7 As described above, after the unmagnetized droplets enter the first magnetic field, the particle cluster is pulled into multiple thin lines, combined with... Figure 8 As shown, after the pre-magnetized droplets enter the first magnetic field, the particle cluster is pulled into a thick line.

[0102] Combination Figure 9 As shown, Figure 9 The left peak in the middle represents the fluorescence intensity characteristic peak of the unmagnetized droplet after entering the first magnetic field, while the right peak represents the fluorescence signal characteristic peak of the premagnetized droplet after entering the first magnetic field. It can be seen that the characteristic peak is more obvious after the premagnetized droplet enters the first magnetic field, which is due to the fluorescence signal identification of the droplet.

[0103] Using the fluorescence signal enhancement device provided in this embodiment, the pre-magnetization component 100 can magnetize the magnetic particles before they enter the first magnetic field, thereby forming an aggregated state. After the magnetized and aggregated magnetic particles enter the first magnetic field, they can be pulled into a thread shape, so that the fluorescent material in the particle cluster can be more fully excited by the laser, thereby improving the droplet recognition accuracy.

[0104] Optionally, the magnetic field strength of the pre-magnetizing magnetic field is greater than the magnetic field strength of the first magnetic field.

[0105] A stronger pre-magnetizing magnetic field can increase the speed at which magnetic particles are magnetized. A weaker first magnetic field can reduce or prevent the magnetic particles from being remagnetized in the first magnetic field, which is beneficial for the magnetic particles in the droplet to be drawn into a linear shape in the first magnetic field.

[0106] Pre-magnetization of magnetic particles in a droplet can be carried out in a container or a pipe. In a container, the droplet is stationary. Placing the container containing the droplet in a pre-magnetizing magnetic field magnetizes the magnetic particles. This method facilitates control over the magnetization of the magnetic particles. In a pipe, the droplet is flowing. Placing the pipe through which the droplet flows in a pre-magnetizing magnetic field magnetizes the magnetic particles as it flows. This method facilitates driving the droplet's flow and allows the pre-magnetized droplet to enter the subsequent first magnetic field.

[0107] Optionally, combined Figures 1 to 4As shown, the pre-magnetization assembly 100 includes a pre-magnetization conduit 110 and a pre-magnetization magnet 120, wherein the pre-magnetization conduit 110 defines a pre-magnetization channel for droplet flow; and the pre-magnetization magnet 120 is used to generate a pre-magnetization magnetic field, at least a portion of which is located within the pre-magnetization magnetic field.

[0108] The pre-magnetizing conduit 110 defines a first flow channel, and the pre-magnetizing magnet forms a pre-magnetizing magnetic field. At least a portion of the first flow channel is located within the pre-magnetizing magnetic field, and the droplet is magnetized in the pre-magnetizing magnetic field as it flows through the portion of the first flow channel located within the pre-magnetizing magnetic field. The pre-magnetizing assembly 100 includes the pre-magnetizing conduit 110 and the pre-magnetizing magnet, which facilitates the magnetization and agglomeration of magnetic particles in the droplet by the fluorescence signal enhancement device. Since the pre-magnetization of the droplet is carried out in the pre-magnetizing conduit 110, the droplet can be pre-magnetized while in flow. This allows for continuous pre-magnetization of the magnetic particles in the droplet, thereby improving the continuity of the pre-magnetization of the droplet by the fluorescence signal enhancement device.

[0109] Optionally, combined Figure 2 As shown, the pre-magnetized magnet includes a pre-magnetized coil 123, which is wound around a pre-magnetized conduit 110. The axis of the pre-magnetized coil 123 is along the length of the pre-magnetized conduit 110. When the coil is energized, a pre-magnetized magnetic field is generated.

[0110] The pre-magnetizing coil 123 is spirally wound around the pre-magnetizing conduit 110. When energized, the pre-magnetizing coil 123 forms an electromagnet, which is used to generate a pre-magnetizing magnetic field. The axis of the pre-magnetizing coil 123 is also the line around which the pre-magnetizing coil 123 spirals. The two ends of the pre-magnetizing conduit 110 serve as the N pole and the S pole, respectively. This arrangement helps to reduce the size of the pre-magnetizing assembly 100, and the strength of the pre-magnetizing magnetic field can be adjusted by regulating the current intensity and / or the number of turns of the pre-magnetizing coil 123.

[0111] 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; and the second pre-magnetized magnet 122 is disposed on the other side of the pre-magnetized pipeline 110.

[0112] The first pre-magnetized magnet 121 and the second pre-magnetized magnet 122 are arranged opposite each other, with the N pole of the first pre-magnetized magnet 121 facing the S pole of the second pre-magnetized magnet 122, or vice versa. Straight magnetic field lines are formed between the first pre-magnetized magnet 121 and the second pre-magnetized magnet 122. When a droplet flows past the pre-magnetized magnets, the direction of the magnetic field lines remains largely unchanged, thus improving the magnetization effect on magnetic particles.

[0113] The first and second pre-magnetizing magnets 122 are disposed opposite each other on both sides of the pre-magnetizing conduit 110. The magnetic force between the first and second pre-magnetizing magnets 121 and 122 acts on the droplets in the pre-magnetizing conduit 110. The strength of the pre-magnetizing magnetic field can be changed by altering the distance between the first and second pre-magnetizing magnets 122. Furthermore, the pre-magnetizing magnets and the pre-magnetizing conduit 110 are separately configured, facilitating the assembly and maintenance of the pre-magnetizing assembly 100 by the user.

[0114] Optionally, a pre-magnetized magnet is used to generate a pre-magnetized magnetic field with changing direction. When the magnetic particles in the droplet are in the pre-magnetized channel, they move and agglomerate under the action of the changing magnetic field force.

[0115] Magnetic particles in a droplet are not only magnetized in a pre-magnetizing magnetic field, but also rotate and move under the influence of magnetic force, thus agglomerating. Magnetic particles can be magnetized in a short time, but agglomeration takes a considerable amount of time. When the direction of the pre-magnetizing magnetic field changes, it intensifies the movement of the magnetic particles in the magnetic field, thereby accelerating their agglomeration. This configuration can improve the agglomeration effect of magnetic particles in a droplet within a pre-magnetizing magnetic field.

[0116] Optionally, the pre-magnetized magnet includes multiple magnet pairs, which are arranged close to the pre-magnetized flow channel. Magnetic field lines are formed between each magnet pair, and the magnetic field lines of the multiple magnet pairs are in different directions to form a pre-magnetized magnetic field with varying directions.

[0117] As one implementation of a pre-magnetizing magnetic field that generates a changing direction, the pre-magnetizing magnet comprises multiple magnet pairs, each pair consisting of two magnets with their N and S poles facing each other. These multiple magnet pairs are arranged along the length of the pre-magnetizing channel, with the two magnets of each pair positioned opposite each other on either side of the channel. The magnetic field lines within the multiple magnet pairs are oriented differently, thus changing the direction of the magnetic force experienced by the droplet as it flows through the pre-magnetizing channel. This arrangement facilitates the aggregation of magnetic particles within the droplet within the pre-magnetizing magnetic field.

[0118] Optionally, multiple magnet pairs are arranged in a spiral pattern.

[0119] Multiple magnet pairs are distributed in a manner similar to the helical arrangement of RNA molecules, so that the magnetic force experienced by the droplets as they flow through the pre-magnetized conduit 110 rotates them in one direction. This allows the magnetic particles to rotate and move more effectively in the pre-magnetized magnetic field, thus facilitating their aggregation.

[0120] 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 wound around the pre-magnetized conduit 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.

[0121] When the direction of the current in the electromagnet is changed, the direction of the electromagnet's magnetic field changes; when the intensity of the current in the electromagnet is changed, the intensity of the electromagnet's magnetic field changes. The pre-magnetizing component 100 includes an electromagnet, and the pre-magnetizing component 100 can form a pre-magnetizing magnetic field with changing direction by changing the current direction and / or current intensity.

[0122] When the pre-magnetized magnet includes a pre-magnetized coil 123 wound around the pre-magnetized conduit 110, a pre-magnetized magnetic field with changing direction can also be formed by changing the direction and / or intensity of the current.

[0123] When the magnetic field strength and / or direction of the pre-magnetizing magnetic field change, the magnetic particles in the droplet can be magnetized more fully and aggregate, which is beneficial for the magnetic particles to be pulled into a thread shape in the first magnetic field.

[0124] Optionally, the pre-magnetized channel is a channel with changing direction, at least part of which is located in the pre-magnetized magnetic field. When the magnetic particles in the droplet move in the channel with changing direction, they are moved and aggregated by the force of the first magnetic field.

[0125] When the direction of the magnetic field remains constant, the flow in the pre-magnetized channel changes direction. When a droplet flows in the pre-magnetized channel, the magnetism of the droplet can change due to the force exerted by the pre-magnetizing magnet in the pre-magnetizing magnetic field. This can also accelerate the aggregation of the magnetic properties of the droplet in the pre-magnetizing magnetic field.

[0126] It should be noted that when the direction and / or intensity of the magnetic field change, the direction of the pre-magnetized flow channel also changes, which can further accelerate the movement of magnetic particles in the droplet in the pre-magnetized magnetic field, thereby causing the magnetic particles in the droplet to aggregate.

[0127] Optionally, the pre-magnetized flow channel includes multiple bends connected end to end to form a pre-magnetized flow channel with changing direction.

[0128] As one implementation of a pre-magnetized flow channel with varying direction, the pre-magnetized flow channel includes multiple bends. These bends are U-shaped or S-shaped and connected end-to-end. This arrangement not only subjectes the magnetic particles in the droplet to a magnetic force with varying direction but also increases the flow formation of the droplet within the pre-magnetized magnetic field. This enhances the pre-magnetization and aggregation effects of the magnetic particles in the droplet by increasing the residence time of the droplet within the pre-magnetized magnetic field.

[0129] Optionally, the pre-magnetized flow channel is a spiral flow channel.

[0130] When the pre-magnetized channel is a spiral channel, the droplet is also subjected to centrifugal force within it. As the droplet moves along the spiral channel, the antigen, antibody, secondary antibody, and magnetic particles within it tend to move towards the outer side of the pre-magnetized channel under the influence of centrifugal force. This not only facilitates the specific binding of antigens, antibodies, secondary antibodies, and magnetic particles but also promotes the aggregation of magnetized magnetic particles.

[0131] Optionally, the pre-magnetized conduit 110 is wound around a pre-magnetized magnet to form a flow channel with varying direction.

[0132] The pre-magnetized conduit 110 is wound around a pre-magnetized magnet, which serves to fix the pre-magnetized conduit 110, thereby improving the structural rigidity of the pre-magnetized assembly 100. Furthermore, the way the pre-magnetized conduit 110 is wound around the pre-magnetized magnet reduces the volume of the pre-magnetized assembly 100.

[0133] The pre-magnetizing conduit 110 is wound around the pre-magnetizing magnet. Firstly, given the limited size of the pre-magnetizing magnet, the length of the pre-magnetizing conduit 110 can be increased, thereby increasing the residence time of the droplet in the pre-magnetizing magnetic field. This improves the pre-magnetizing effect of the pre-magnetizing magnetic field on the magnetic particles. Secondly, the pre-magnetizing conduit 110 is wound around the pre-magnetizing magnet in a manner where its radial direction cuts the magnetic field lines of the pre-magnetizing magnet. When the droplet flows in the pre-magnetizing conduit 110, the magnetic field lines acting on the magnetic particles are in substantially the same direction, further enhancing the pre-magnetizing effect of the pre-magnetizing magnetic field on the magnetic particles.

[0134] Optionally, the pre-magnetizing magnetic field includes a first part and a second part, wherein the direction of the magnetic field in the first part remains unchanged, and the direction of the magnetic field in the second part changes over time.

[0135] Magnetic particles in a droplet are magnetized in a pre-magnetizing magnetic field. The magnetized magnetic shells then aggregate during the flow process both within and after leaving the pre-magnetizing magnetic field. For the aggregation of magnetic particles, it is advantageous for the direction of the pre-magnetizing magnetic field to change; for the magnetization of magnetic particles, it is advantageous for the direction of the pre-magnetizing magnetic field to remain unchanged.

[0136] Therefore, the pre-magnetizing magnetic field consists of a first part and a second part. The direction of the magnetic field in the first part remains constant, while the direction of the magnetic field in the second part changes over time. In this way, the magnetic particles are magnetized in the first part of the pre-magnetizing magnetic field and aggregate in the second part. Although the magnetic particles are still magnetized in the second part of the pre-magnetizing magnetic field, and aggregation still occurs in the first part, this arrangement can separate the pre-magnetization and aggregation of the magnetic particles to a certain extent, thereby improving both the magnetization and aggregation effects.

[0137] Optionally, the pre-magnetized magnet includes an AC electromagnet, the second part of which forms a pre-magnetized magnetic field when the AC electromagnet is energized.

[0138] The direction of the magnetic field of an alternating current electromagnet changes with the direction of the current. Magnetic particles can move more in the second part of the pre-magnetized magnetic field, thus better agglomerating.

[0139] Optionally, the pre-magnetized magnet includes a DC electromagnet, the first part of which forms a pre-magnetized magnetic field when the DC electromagnet is energized.

[0140] The direction of the magnetic field of a DC electromagnet remains unchanged, and the strength of the first part of the pre-magnetizing magnetic field formed by the DC electromagnet is easy to adjust.

[0141] Optionally, the pre-magnetized conduit 110 is a flexible hose, and the length of the portion located in the pre-magnetized magnetic field can be adjusted by moving the pre-magnetized conduit 110.

[0142] For the pre-magnetization of magnetic particles, a short pre-magnetization time results in an insignificant magnetization effect, making it difficult for the magnetic particles to achieve an ideal agglomeration state. Conversely, a longer pre-magnetization time leads to a compact agglomeration of magnetic particles, making it difficult to stretch them into a linear shape within the first magnetic field. With a constant droplet flow rate, the length of the pre-magnetization tube 110 within the pre-magnetization magnetic field determines the duration the droplet remains there. The required pre-magnetization time and magnetic field strength vary depending on the droplet. With a constant magnetic field strength, the pre-magnetization time of the droplet within the pre-magnetization magnetic field can be adjusted by regulating the length of the portion of the pre-magnetization tube 110 within the pre-magnetization magnetic field. This configuration allows users to adjust the degree of pre-magnetization as needed. The adjustable length of the pre-magnetization tube 110 within the pre-magnetization magnetic field allows for adjustment of the pre-magnetization time, thereby achieving the desired pre-magnetization effect for the magnetic particles in the droplet. For example, as a length adjustment method, the pre-magnetized pipe 110 is a flexible pipe, and the length of the part of the pre-magnetized pipe 110 located in the pre-magnetized magnetic field is adjusted by changing the number of turns of the pre-magnetized pipe 110 in the pre-magnetized magnetic field.

[0143] Optionally, at least a portion of the pre-magnetized conduit 110 is spirally disposed in the pre-magnetized magnetic field.

[0144] This configuration increases the length of the pre-magnetizing conduit 110, thereby increasing the residence time of the droplet in the pre-magnetizing magnetic field and improving the pre-magnetizing effect of the magnetic field on the magnetic particles. It should be noted that initially, the magnetic particles exhibit N and S poles macroscopically upon entering the pre-magnetizing magnetic field. During the subsequent movement of the droplet, the magnetic particles, under the influence of the magnetic force, can align their internal magnetic field lines with those of the pre-magnetizing magnetic field, that is, adapting to the change in the direction of the magnetic field lines through their own rotation. Although the spiral shape of the pre-magnetizing conduit 110 causes multiple changes in the radial direction of the magnetic field lines, increasing the residence time of the magnetic particles in the pre-magnetizing magnetic field generally improves the pre-magnetizing effect on the magnetic particles.

[0145] Optionally, combined Figures 1 to 4 As shown, the fluorescence signal enhancement device also includes a flow channel assembly that defines a droplet flow channel 311, at least a portion of which is located in the first magnetic field.

[0146] The flow rate of the droplet channel 311 is set to allow only one droplet to pass through at a time. The channel assembly cooperates with the first magnet 210. The pre-magnetized droplet enters the droplet channel 311 of the channel assembly, and under the action of the first magnetic field, the agglomerated magnetic particles in the droplet are drawn into a linear shape. When the droplet is pre-magnetized in a container, the channel assembly has an opening for filling the droplet, which is connected to the droplet channel 311. When the droplet is pre-magnetized in the pre-magnetization pipe 110, the outlet end of the pre-magnetization pipe 110 is connected to the inlet section of the droplet channel 311.

[0147] The presence of a flow channel assembly, with the droplet flow channel 311 of the flow channel assembly at least partially located in the first magnetic field, allows the droplet to have a relatively fixed position when flowing through the first magnetic field, which is beneficial for exciting and detecting fluorescent signals in the droplet.

[0148] Optionally, the pre-magnetized channel is connected to the droplet channel 311, and the droplet channel 311 is located after the pre-magnetized channel along the droplet flow direction.

[0149] After passing through the pre-magnetization component 100, the droplet enters the droplet channel 311. The magnetic particles within the droplet are drawn into a linear shape after flowing a certain distance along the droplet channel 311. This arrangement facilitates fluorescence signal recognition of the droplet and also allows for observation and photography of the droplet. Furthermore, this arrangement ensures continuous flow of the droplet within the pre-magnetization channel and the droplet channel 311, enhancing the continuous operation capability of the fluorescence signal enhancement device.

[0150] Optionally, the magnet assembly 200 includes a first magnet 210 and a second magnet 220, wherein the first magnet 210 is disposed on one side of the droplet channel 311; the second magnet 220 is disposed on the other side of the droplet channel 311; wherein the length direction of the droplet channel 311 is along the direction that cuts the magnetic field lines between the first magnet 210 and the second magnet 220.

[0151] 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 makes the magnetic field lines between the first magnet 210 and the second magnet 220 straight, which helps to pull multiple components, including magnetic particles, into a straight line, thereby enhancing the fluorescence signal and improving the droplet recognition accuracy.

[0152] Optionally, combined Figures 1 to 4As shown, the flow channel assembly includes a microfluidic chip, which defines a chip flow channel for droplet flow within itself. The chip flow channel includes a sheath fluid inflow channel 312, a sample fluid inflow channel 313, and a droplet flow channel 311. At least a portion of the droplet flow channel 311 is located in a first magnetic field. The inlet end of the sample fluid inflow channel 313 is used to fill droplets that have passed through a pre-magnetized magnetic field. The outlet end of the sample fluid inflow channel 313 and the outlet end of the sheath fluid inflow channel 312 are connected to the inlet end of the droplet flow channel 311. The droplets that have passed through the pre-magnetized magnetic field mix with the sheath fluid and then enter the droplet flow channel 311.

[0153] Sheath fluid is a liquid medium used to focus water-in-oil droplets or samples. When the water-in-oil droplets or samples are compressed by the sheath fluid, they form a stable liquid flow environment together with the sheath fluid, allowing the water-in-oil droplets or samples to pass through the droplet channel in a single file, approximately along the central axis of the droplet channel. Exemplarily, the sheath fluid is an oil phase. The inlet end of the sample liquid inflow channel 313 is used to fill the channel with sample liquid, and the sample liquid injection channel has a sample liquid injection port 3131. The sample liquid contains water-in-oil droplets, and each droplet includes at least one fluorescently identifiable marker. Exemplarily, the droplet sorting system provided in this embodiment can be used to sort biological samples such as cells, bacteria, and viruses. Each droplet includes at least one cell, bacterium, or virus, and a fluorescently identifiable marker.

[0154] 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 allows for non-destructive droplet sorting, ensuring the activity and integrity of the sample within the droplet.

[0155] The microfluidic chip 310 is configured with a sheath fluid inflow channel 312 and a sample fluid inflow channel 313. By controlling the pressure of the sheath fluid inflow channel 312 and the sample fluid inflow channel 313, the distance between two adjacent droplets entering the droplet channel 311 and the flow rate of the droplets can be changed.

[0156] The pre-magnetized droplets are water-in-oil droplets encapsulated in sheath fluid. However, the water-in-oil droplets serve to isolate the antibodies and antigens from interfering with each other between adjacent droplets. After the sample solution enters the flow channel 313 of the microfluidic chip 310, the water-in-oil droplet mixes again with the sheath fluid in the flow channel 312, allowing the droplet to flow within the droplet channel 311 at a preset flow rate and preset adjacent distance. This configuration facilitates the identification, observation, and sorting of droplets within the microfluidic chip 310.

[0157] Optionally, the microfluidic chip 310 is also configured with a pre-magnetized channel. The part of the microfluidic chip 310 that is configured with the pre-magnetized channel serves as the aforementioned pre-magnetized conduit 110. After the droplet flows through the pre-magnetized channel, it enters the sample liquid inflow channel 313.

[0158] This configuration can improve the integration of the droplet recognition device, thereby reducing its cost.

[0159] Optionally, the pre-magnetized magnet includes a first pre-magnetized magnet 121 and a second pre-magnetized magnet 122, which are respectively disposed on the upper and lower surfaces of the microfluidic chip 310.

[0160] With this configuration, the droplet flows in the pre-magnetized flow along the direction that cuts the magnetic field lines of the pre-magnetized magnet, which is beneficial for magnetizing the magnetic particles in the droplet. Furthermore, the distance between the magnetic particles and the first and second pre-magnetized magnets 122 does not change significantly as the droplet flows. This reduces or prevents sample damage caused by the magnetized magnetic particles squeezing the droplet as they move toward the first or second pre-magnetized magnet 121 or 122.

[0161] Optionally, combined Figures 12 to 15 As shown, the flow channel assembly also includes a support frame 320, which includes a base plate, a first side plate 322 and a second side plate 323, with the first side plate 322 and the second side plate 323 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 base plate.

[0162] The support frame 320 is used to fix the microfluidic chip 310. Specifically, the bottom of the microfluidic chip 310 rests on the base plate of the support frame 320, and the two sides of the microfluidic chip 310 are respectively held by the first side plate 322 and the second side plate 323 of the support frame 320. This arrangement is beneficial for fixing the microfluidic chip 310 and facilitates the identification and observation of droplets in the droplet channel 311.

[0163] Optionally, the fluorescence signal enhancement device further includes a carrier plate 710 and a fixing component 720, wherein the carrier plate 710 has an installation window; and the fixing component 720 is used to fix the flow channel assembly to the installation window.

[0164] The chip assembly 300 is fixed to the mounting window, and the droplet channel 311 of the microfluidic chip 310 is exposed on both the downward and upward sides, which is beneficial for fluorescent identification and observation of droplets in the droplet channel 311.

[0165] Optionally, the fixing component 720 includes a first clamping member 721 and a second clamping member 722, wherein the first clamping member 721 is used to fix a first end of the chip assembly 300; and the second clamping member 722 is used to fix a second end of the chip assembly 300.

[0166] By clamping both ends of the chip assembly 300 with the first clamping member 721 and the second clamping member 722, the chip assembly 300 can be better fixed to the carrier plate 710.

[0167] Optionally, the pre-magnetized component 100 is fixed to the carrier plate 710.

[0168] This configuration not only facilitates the installation of the pre-magnetization component 100, but also allows users to adjust the length of the pre-magnetization pipeline 110 within the pre-magnetization magnetic field.

[0169] Optionally, the magnet assembly 200 includes a first magnet 210 and a second magnet 220, wherein the first magnet 210 is disposed on the inward side of the first side plate 322; and the second magnet 220 is disposed on the inward side of the second side plate 323.

[0170] 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 to fixing the magnet assembly 200.

[0171] Combination Figures 1 to 15 As shown, this embodiment of the present disclosure provides a fluorescence signal detection device, including the above-mentioned fluorescence signal enhancement device, laser component, and fluorescence detection component 500. The laser component is used to emit laser light to a magnetic particle that has been stretched into a wire shape, and the fluorescent marker in the droplet is excited by the laser to emit fluorescence. The fluorescence detection component 500 is used to detect the fluorescence emitted by the fluorescent marker in the droplet.

[0172] After the droplet flows through the first section of the droplet channel 311, multiple particle clusters composed mainly of magnetic particles within the droplet form a linear shape. At this point, an excitation laser is emitted to the droplet via a laser component, causing the antigen and secondary antibody within the multiple particle clusters to fluoresce. By detecting the fluorescence intensity of the antigen and the secondary antibody, it can be determined whether the droplet is the target droplet. This setup facilitates fluorescence recognition of droplets and improves the accuracy of droplet recognition.

[0173] Optionally, the laser component is disposed below the support plate 710 and the light emission direction is towards the droplet channel 311 located in the first magnetic field; and / or, the fluorescence detection component 500 is disposed below the support plate 710 and the detection direction is towards the droplet channel 311 located in the first magnetic field.

[0174] The laser component and fluorescence detection component 500 are located below the carrier plate 710, which will not obstruct the microfluidic chip and is beneficial for users to observe the droplets in the droplet channel 311.

[0175] Optionally, the base plate of the support frame 320 has an observation window, and at least the first part of the microfluidic chip corresponding to the observation window is made of transparent material; wherein, the light emission direction of the laser component is towards the observation window; and / or, the detection position of the fluorescence detection component 500 corresponds to the observation window.

[0176] This configuration facilitates the laser's action on the particle clusters within the droplet and also allows the fluorescence detection component 500 to receive the fluorescence signal from the particle clusters.

[0177] Optionally, the fluorescence detection component 500 includes a photomultiplier tube.

[0178] A photomultiplier tube amplifies an optical signal and converts it into an electrical signal, thus reflecting the intensity of the fluorescence signal. The fluorescence detection component 500 includes a photomultiplier tube, which can improve the accuracy of droplet recognition.

[0179] Optionally, the fluorescence detection component 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.

[0180] By detecting two types of fluorescence signals using the first photomultiplier tube 510 and the second photomultiplier tube 520, interference between the fluorescence signals can be reduced or avoided, which is beneficial to improving the accuracy of droplet recognition.

[0181] Optionally, the laser assembly includes a first laser source 410 and a second laser source 420, wherein the first laser source 410 is used to excite the fluorescent material of the antigen, and the second laser source 420 is used to excite the fluorescent material of the secondary antibody.

[0182] By exciting the antigen and secondary antibody fluorescent substances respectively by the first laser light source 410 and the second laser light source 420, the droplet identification device can obtain more accurate fluorescence information, which is beneficial for the droplet identification device to determine whether the droplet is the target droplet.

[0183] Optionally, the laser assembly also includes an optical coaxial system 430, which transmits light emitted from the first laser source 410 and the second laser source 420 to the observation window.

[0184] The laser assembly includes an optical coaxial system 430. The mounting positions of the first laser source 410 and the second laser source 420 are unrestricted, which is beneficial for the miniaturization of the droplet recognition device. The optical axis collimation of the optical coaxial system 430 is high, the laser transmission loss is small, and the laser transmission efficiency is high.

[0185] Optionally, the light emitted by the laser assembly is directed toward the observation window.

[0186] This configuration is advantageous for the laser component to excite fluorescent substances in the particle clusters.

[0187] Optionally, the detection position of the fluorescence detection component 500 corresponds to the observation window.

[0188] This configuration facilitates the detection of fluorescence signals in droplets by the fluorescence detection device.

[0189] Combination Figures 1 to 15 As shown, this embodiment of the present disclosure provides a droplet observation device, including the above-mentioned fluorescence signal enhancement device, light source assembly 620 and imaging assembly, wherein the light source assembly 620 emits light in the direction of the droplet in the first magnetic field; the imaging assembly is positioned in the direction of the image of the droplet in the first magnetic field.

[0190] By incorporating an imaging component, image information of the sample within the target droplet can be acquired, facilitating observation and analysis by the user. The imaging component can also acquire image information of suspected target droplets, allowing the user to adjust the settings of the droplet recognition device based on these images, thereby further improving the accuracy of droplet recognition.

[0191] Optionally, the imaging components include a high-speed camera 610.

[0192] Even when the droplets are flowing at high speeds, the high-speed camera 610 can still obtain relatively clear images of the droplets. The imaging assembly, including the high-speed camera 610, can increase the speed of droplet flow in the droplet observation device.

[0193] 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 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 channel 311 located in the first magnetic field.

[0194] The light source assembly 620 illuminates from above, and the droplet appears as a silhouette in the high-speed camera 610. The image information of the sample within the droplet can still be reconstructed through the contrast between light and shadow in the image. Compared to imaging with emitted light, this method provides better image information regarding the depth direction of the droplet. Furthermore, the top-down illumination of the light source assembly 620 avoids direct light shining into the user's eyes.

[0195] The imaging device is located below the support plate 710, which can reduce or avoid obstruction of the droplet flow channel 311 and facilitate users to monitor the operation status of the droplet observation device with the naked eye.

[0196] Optionally, the light source assembly 620 opens synchronously with the shutter of the high-speed camera 610.

[0197] The light source assembly 620 is activated only when the shutter of the high-speed camera 610 is open, which reduces light pollution from the light source assembly 620 and extends its service life.

[0198] Optionally, the base plate of the support frame 320 has an observation window, and the microfluidic chip is made of transparent material at least the first part of the observation window, with the imaging position of the imaging component facing the first part of the observation window.

[0199] This is beneficial for the imaging device to acquire droplet images and can reduce or avoid the imaging device from obstructing the microfluidic chip.

[0200] Optionally, the fluorescent recognition component is disposed below the carrier plate 710.

[0201] Similarly, this reduces the impact 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 shifting or being damaged during the use of the droplet recognition device.

[0202] Optionally, the upward-facing side of the microfluidic chip, at least the second part 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 part of the microfluidic chip.

[0203] The microfluidic chip can be entirely made of transparent material, which facilitates fluorescence signal recognition of droplets in the droplet channel 311 and the acquisition of images of the droplets. Alternatively, the microfluidic chip can be partially transparent, provided that at least the portion corresponding to the observation window is transparent. This facilitates imaging by the imaging device and allows the user to visually observe the droplets in the droplet channel 311.

[0204] This disclosure also provides a droplet sorting system, which includes a flow channel assembly, the aforementioned fluorescence signal enhancement device or fluorescence signal detection device, and a sorting device. The flow channel assembly defines a droplet flow channel 311 for droplet flow, a first outlet flow channel 314, and a second outlet flow channel 315. The fluorescence signal enhancement device generates a pre-magnetizing magnetic field and a first magnetic field. Magnetic particles in the droplet are magnetized and aggregated in the pre-magnetizing magnetic field, and the aggregated magnetic particles are pulled into a linear shape in the first magnetic field. The identification device excites the droplets to emit fluorescence and marks droplets that meet the fluorescence conditions as target droplets. The sorting device is configured corresponding to the outlet section of the droplet flow channel 311. Target droplets flowing through the outlet section of the droplet flow channel 311 enter the first outlet flow channel 314 under the deflection effect of the sorting device, while non-target droplets enter the second outlet flow channel 315.

[0205] The flow channel assembly defines a droplet flow channel 311, a first outlet flow channel 314, and a second outlet flow channel 315 for droplet flow. The inlet ends of the first outlet flow channel 314 and the second outlet flow channel 315 are connected to the outlet end of the droplet flow channel 311. Droplet fluorescence signal recognition is performed in the droplet flow channel 311. The identified target droplet flows out from the first outlet flow channel 314, and the non-target droplet flows out from the second outlet flow channel 315.

[0206] The droplet sorting system provided in this embodiment further includes a fluorescence signal enhancement device and an identification device to identify target droplets. The fluorescence signal enhancement device enhances the fluorescence signal of the droplets to make them easier for the identification device to recognize in the droplet flow channel 311. Specifically, the fluorescence signal enhancement device generates a pre-magnetizing magnetic field and a first magnetic field. The pre-magnetizing magnetic field causes the magnetic particles to exhibit magnetism macroscopically, i.e., to display N and S poles. Specifically, the magnetic particles rearrange themselves according to the direction of the magnetic field lines in the pre-magnetizing magnetic field, thereby exhibiting magnetism macroscopically. 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 aggregated. The aggregated state can be defined as the distance between at least two magnetic particles being less than or equal to the diameter of a droplet.

[0207] Using the droplet sorting system provided in this embodiment, the fluorescence signal of the droplets is enhanced, making the fluorescence signal of the target droplet more distinct from that of the non-target droplet, thus improving the accuracy of droplet sorting.

[0208] Optionally, the sorting device includes a sorting electromagnet, which is disposed in the liquid outlet section of the droplet channel 311. The sorting electromagnet is activated when the target droplet flows through the liquid outlet section of the droplet channel 311 so that the target droplet is deflected to the first liquid outlet channel 314 under the action of the magnetic field force.

[0209] The sorting electromagnet corresponds to the outlet section of the droplet channel 311 and is located on the same side as the first outlet channel 314. When the target droplet flows through the outlet section of the droplet channel 311, the sorting electromagnet is energized. After being energized, the sorting electromagnet exerts a pulling effect on the magnetic particles in the droplet, thereby deflecting the target droplet to the first outlet channel 314. This configuration allows for convenient sorting of target droplets. It should be noted that when a non-target droplet flows through the outlet section of the droplet channel 311, the sorting electromagnet is not energized, and the non-target droplet flows to the second droplet channel 311 under inertia.

[0210] Optionally, the sorting device also includes a sorting electromagnet, which is disposed in the liquid outlet section of the droplet channel 311. The sorting electromagnet is activated when a non-target droplet flows through the liquid outlet section of the droplet channel 311, so that the non-target droplet is deflected to the second liquid outlet channel 315 under the action of the magnetic field force.

[0211] In this situation, when the target droplet flows through the outlet end of the droplet channel 311, the sorting electromagnet is not energized, and the target droplet flows to the first outlet channel 314 under the action of inertia.

[0212] With this configuration, the magnetic particles in the target droplet will not be affected by the magnetic field force, which can reduce or avoid the damage to the sample in the droplet when the magnetic particles move under the influence of the magnetic field force.

[0213] Optionally, combined Figure 1 As shown, the sorting device includes a first air pump 850, which is disposed in a 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.

[0214] When the first air pump 850 is working, it applies positive pressure to the first liquid outlet channel 314. This creates a 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 towards the second liquid outlet channel 315 under the influence of the pressure difference. The air pump has a fast response speed, enabling high-speed sorting of droplets. In addition, when the air pump applies positive pressure to the first liquid outlet channel 314, the droplets are subjected to uniform force, and the samples in the droplets are less likely to be damaged.

[0215] It should be noted that the shape of the flow channel can be designed so that both target and non-target droplets enter the first outlet flow channel 314 when the first air pump 850 is not operating. Thus, simply starting and stopping the first air pump 850 allows the target droplets to enter the first outlet flow channel 314 and the non-target droplets to enter the second outlet flow channel 315. For example, the inlet section of the first outlet flow channel 314 is located on the extension line of the outlet section of the droplet flow channel 311, and the inlet section of the second outlet flow channel 315 forms an angle of less than or equal to 150° with the outlet end of the droplet flow channel 311.

[0216] Optionally, the sorting device includes a second air pump 860 disposed in the second liquid outlet channel 315, and the second air pump 860 is configured to apply positive pressure to the second liquid outlet channel 315 when the target droplet flows through the sorting device.

[0217] When the second air pump 860 is working, it applies positive pressure to the second liquid outlet channel 315. This creates a pressure difference between the first liquid outlet channel 314 and the second liquid outlet channel 315. When the target droplet flows through the outlet section of the droplet channel 311, it is deflected towards the first liquid outlet channel 314 under the influence of the pressure difference. This also enables high-speed sorting of droplets and makes it less likely to damage the sample in the target droplet when it is deflected.

[0218] It should be noted that the shape of the flow channel can be designed so that both target and non-target droplets enter the second outlet flow channel 315 when the second air pump 860 is not operating. Thus, simply starting and stopping the second air pump 860 allows the target droplets to enter the first outlet flow channel 314 and the non-target droplets to enter the second outlet flow channel. For example, the inlet section of the second outlet flow channel 315 is located on the extension line of the outlet section of the droplet flow channel 311, and the inlet section of the first outlet flow channel 314 forms an angle of less than or equal to 150° with the outlet end of the droplet flow channel 311.

[0219] Furthermore, the sorting device can simultaneously include the aforementioned first air pump 850 and second air pump 860. When the sorting device includes the first air pump 850 and the second air pump 860, the target droplets enter the first outlet channel 314 under the action of a pressure difference, and the non-target droplets enter the second outlet channel 315 under the action of a pressure difference. This allows for better droplet sorting.

[0220] 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 disposed on one side of the first liquid outlet channel of the droplet channel; the negative electrode 820 is disposed on one side of the first liquid outlet channel of the droplet channel. When the positive electrode 810 and the negative electrode 820 are energized, they form an electric field acting on the liquid outlet section of the droplet channel 311. The target droplet is deflected to the first liquid outlet channel 314 under the action of electrophoretic force.

[0221] The length direction of the droplet channel is the flow direction of the droplet, which serves as the axis of the droplet channel. Using the length direction of the droplet channel as a dividing line, the plane containing the droplet channel is divided into two regions: one region is called the first side, and the other region is called the second side. The first outlet channel is located in the first region, and the positive and negative electrodes are also located in the first region. The first outlet channel, the positive electrode, and the negative electrode are located on the same side of the droplet channel.

[0222] Driven by an external force, the droplet flows along the droplet flow path, moving from the inlet end to the outlet end. Upon reaching the outlet end, the droplet enters the effective range of the electrode assembly. When the electrode assembly is energized, an electric field is generated, causing the droplet to deflect towards the side closer to the positive electrode 810 and negative electrode 820 under the influence of this electric field. As the droplet continues to flow under the external force, it is more likely to enter the first outlet channel as it is closer to the side where the first outlet channel is located. In this process, it can be considered that the target droplet is deflected by the electrophoretic force, thus enabling it to enter the first outlet channel.

[0223] Optionally, combined Figure 11 As shown, the sorting device includes multiple positive electrodes 810 and multiple negative electrodes 820, which are alternately arranged and connected to each other.

[0224] Multiple positive and 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 pulls the droplet towards the side containing either the positive or negative electrode. This arrangement allows for multiple pulls on the droplet, deflecting it towards the first outlet channel. This reduces or prevents excessive electrophoretic forces from causing the droplet to break. Furthermore, the pull effect of multiple positive and negative electrodes increases the droplet sorting throughput.

[0225] It should be noted that alternating current can be applied to both the positive and negative electrodes. When alternating current is applied, the alternating electric field between the positive and negative electrodes can also generate an electrophoretic force that deflects the droplet. In this case, the positive and negative electrodes are only used to distinguish opposite electrodes and to restrict the application of either direct current (DC) to the positive electrode or DC to the negative electrode.

[0226] Electrophoretic forces can be applied to droplets sequentially and repeatedly by controlling the on / off state of multiple positive electrodes, thereby deflecting the droplets. Connecting multiple negative electrodes reduces the complexity of setting them up.

[0227] Optionally, the sorting device includes multiple positive electrodes and two negative electrodes, with the two negative electrodes located on either side of the multiple positive electrodes.

[0228] When any one of the multiple positive electrodes is energized, it creates an electric field between itself and the two negative electrodes. When the distances of the positive electrodes to the two negative electrodes differ, the target droplet is deflected towards the first outlet channel under the influence of electrophoretic force. Using multiple positive electrodes in combination with two negative electrodes reduces the number of negative electrodes required, thus simplifying their arrangement.

[0229] Optionally, the sorting device includes a plurality of positive electrodes 810, the distances of which from the plurality of positive electrodes 810 to the droplet channel 311 are not exactly the same.

[0230] The sorting device includes multiple positive electrodes 810, which can form an electric field with a certain gradient. Droplets tend to move in the direction of the electric field gradient in the electric field, thus being better deflected towards the corresponding flow channel.

[0231] Optionally, multiple positive electrodes are activated sequentially as the target droplet flows through the outlet section of the droplet channel.

[0232] If a droplet is simultaneously subjected to electrophoretic forces from multiple electric fields, its movement intention becomes unclear. Multiple positive electrodes are activated sequentially, ensuring that the target droplet is deflected by only one electric field within a given time period. This configuration helps the sorting device deflect the target droplet to the first outlet channel.

[0233] Optionally, combined Figures 16 to 21 As shown, the sorting device includes an electrode assembly, which includes at least one electrode unit disposed on one side of the droplet channel 311. The electrode unit includes one or more positive electrodes 810 and two negative electrodes 820. The positive electrodes 810 are arranged on the first side of the droplet channel 311, and the two negative electrodes 820 are arranged on the first side of the droplet channel 311, and the two negative electrodes 820 are respectively located on both sides of the one or more positive electrodes 810.

[0234] The electrode assembly provided in this disclosure can be applied to a sorting device or a droplet sorting system.

[0235] The sorting device or droplet sorting system has the function of identifying target droplets, and the electrode assembly is used to drive the target droplet to move towards the target side. At the electrode assembly, when the electrode is energized, the surface tension of the droplet is affected by the surface charge, and the change in surface tension causes the droplet shape to change. When the droplet shape changes, it undergoes directional movement in the droplet channel, that is, it moves towards the side where the electrode assembly is located. This movement of the droplet under the action of the electric field can also be regarded as the movement of the droplet under the action of electrophoretic force.

[0236] It should be noted that alternating current can be applied to both the positive and negative electrodes. When alternating current is applied, the alternating electric field between the positive and negative electrodes can also generate electrophoretic force, causing the droplet to deflect. In this case, the positive and negative electrodes are only used to distinguish opposite electrodes, and do not restrict the positive electrode to only being able to be energized with direct current or the negative electrode to only being able to be energized with direct current.

[0237] Specifically, the droplet sorting system includes a sheath fluid inflow channel 312, a sample fluid inflow channel 313, a droplet channel 311, a first outlet channel 314, and a second outlet channel 315.

[0238] The sheath fluid inflow channel 312 is used for filling with sheath fluid, and the sheath fluid inflow channel has a sheath fluid injection port 3121. The inlet end of the sample fluid inflow channel 313 is used for filling with sample fluid, and the sample fluid injection channel has a sample fluid injection port 3131.

[0239] For example, the identification markers include multiple magnetic particles, multiple fluorescently labeled antigens, and fluorescently labeled secondary antibodies. After the antigen is recognized, the cell produces multiple antibodies, and the antigen can bind to multiple antibodies. The magnetic particles have multiple functional groups on their surface, which can bind to multiple antibodies secreted by the cell. The secondary antibody binds only to specific antibodies. If a target particle cluster containing antigen, antibody, magnetic particles, and secondary antibody is present in a droplet, the cell in that droplet is considered a target cell capable of producing high-affinity antibodies, and that droplet is considered a target droplet.

[0240] The water-in-oil droplets in the sample solution are used to isolate neighboring cells. These water-in-oil droplets are further mixed with the sheath fluid flowing into the sheath fluid channel, thereby flowing in the droplet channel 311 at a preset flow rate and a preset adjacent distance.

[0241] This facilitates the identification, observation, and sorting of droplets within the droplet sorting system.

[0242] During the process of pulling a target droplet toward the target side of the droplet channel, if the force is small and the duration is short, the target droplet is unlikely to deflect. If the force is large, the droplet is easily broken. The electrode assembly provided in this disclosure includes at least one electrode unit. The electrode unit includes at least one or more positive electrodes and two negative electrodes, with the two negative electrodes located on either side of the one or more positive electrodes.

[0243] One or more positive electrodes and two negative electrodes in the electrode unit respectively form an electric field acting on the target droplet. As the target droplet flows through the electrode assembly, it experiences a uniform and continuous pulling force, and is then deflected to the target side of the droplet flow channel. Because the electric field formed by the positive electrode and the two negative electrodes has a large range of action, the droplet in the target droplet is not easily torn apart. The electric field formed by the electrode unit acts for a relatively long time, making it easier for the target droplet to deflect to the target side.

[0244] When an electrode unit includes one positive electrode, the positive electrode and the two negative electrodes form two electric fields. The two electric fields are located on opposite sides of the positive electrode, making it difficult for electric fields to superimpose or interfere with each other.

[0245] Using the electrode assembly provided in the embodiments of this disclosure, the electrode unit can provide a continuous and uniform pulling force to the target droplet, thereby allowing the droplet to pass through the droplet channel at a higher speed, which can significantly improve the droplet throughput; by providing a pulling force to the target droplet through multiple electric fields of the electrode unit, the pulling force on the target droplet is relatively gentle, and the droplet is not easily torn apart.

[0246] Optionally, combined Figure 16 , Figure 17 As shown, the electrode unit includes multiple positive electrodes, and two negative electrodes are located on both sides of the multiple positive electrodes.

[0247] When the electrode unit includes multiple positive electrodes, the multiple positive electrodes and the two negative electrodes respectively form multiple electric fields. When the target droplet flows through the electrode assembly, the electrophoretic force it experiences first gradually increases and then gradually decreases, and the target droplet is deflected more fully in the droplet channel.

[0248] Optionally, along the droplet flow direction, the distance between the multiple positive electrodes and the droplet channel gradually increases.

[0249] As the target droplet flows through the electrode unit, it is deflected towards the first side of the droplet channel under the deflection force applied by the electrode assembly. The distance between the target droplet and the multiple positive electrodes gradually decreases, and the electric field force it experiences gradually increases. This gradual increase in the distance between the multiple positive electrodes and the droplet channel ensures that the target droplet experiences a uniform force as it flows through the electrode assembly. Furthermore, this arrangement allows for approximately equal voltages to be applied to the multiple positive electrodes, facilitating voltage control of the multiple positive electrodes.

[0250] Optionally, the voltage of the multiple positive electrodes gradually decreases along the direction of droplet flow.

[0251] This configuration ensures that the force exerted on the target droplet remains essentially constant as it flows through the electrode assembly, thereby reducing the risk of the droplet breaking. Furthermore, by setting the voltage of the multiple positive electrodes to decrease gradually, the multiple positive and negative electrodes of the electrode assembly can be positioned as close as possible to the droplet flow channel, which is beneficial for the placement of multiple positive and negative electrodes.

[0252] Optionally, combined Figure 17 As shown, the electrode assembly includes multiple electrode units 80, which are arranged on the first side of the droplet channel.

[0253] The electrode assembly comprises multiple electrode units, which can further increase the effective range of the electric field formed by the electrode assembly. With a constant droplet flow velocity, the target droplet spends more time flowing in the outlet section of the droplet channel, thus increasing the duration of the target droplet's interaction with the electric field force of the electrode assembly. This allows the electrode assembly to be supplied with a lower voltage, thereby reducing electromagnetic interference from the electrode assembly to the droplet sorting system and lowering the risk of electrode breakdown. With a constant voltage in the electrode assembly, droplets can pass through at higher flow velocities, increasing the number of droplets sorted per unit time, thus improving the sorting throughput of the droplet sorting system.

[0254] Optionally, along the droplet flow direction, the distance between multiple electrode units and the droplet flow channel gradually increases.

[0255] As the target droplet flows through the electrode units, it is deflected towards the first side of the droplet channel under the deflection force applied by the electrode assembly. The distance between the target droplet and the electrode units gradually decreases, and the electric field force it experiences gradually increases. The gradually increasing distance between multiple electrode units and the droplet channel ensures that the target droplet experiences a uniform force as it flows through the electrode assembly. Furthermore, this arrangement allows for approximately equal voltage to be applied to multiple electrode units, facilitating voltage control of these units.

[0256] Optionally, along the droplet flow direction, the voltage of the positive electrode of the multiple electrode units gradually decreases.

[0257] This ensures that the force exerted on the target droplet remains essentially constant as it flows through the electrode assembly, thereby reducing the risk of the droplet breaking. Furthermore, by setting the voltage of the multiple positive electrodes to decrease gradually, the multiple positive and negative electrodes of the electrode assembly can be positioned as close as possible to the droplet flow channel, which is beneficial for the arrangement of multiple positive and negative electrodes.

[0258] Optionally, combined Figure 18 As shown, two adjacent electrode units 80 share a single negative electrode 820.

[0259] By having two adjacent electrode units share a single negative electrode, the number of negative electrodes can be reduced, thus lowering the cost of the electrode assembly. Furthermore, this ensures that the electrophoretic force experienced by the target droplet at the electrode assembly is continuous and uniform. This improves the success rate of deflecting the target droplet and increases the throughput of the droplet sorting system.

[0260] Optionally, combined Figure 19 As shown, the electrode unit includes one positive electrode and two negative electrodes, and the positive and negative electrodes of the electrode assembly are alternately arranged.

[0261] In one implementation, each electrode unit includes one positive electrode and two negative electrodes. Two adjacent electrode units share a single negative electrode, and the electrodes of the electrode assembly are arranged in an alternating pattern of positive and negative electrodes. With this arrangement, the multiple electric fields formed by the electrode assembly through the multiple positive and negative electrodes are relatively uniform, and adjacent electric fields are less likely to overlap.

[0262] Optionally, the negative electrode 820 of the electrode assembly is connected, and the positive electrode 810 of the electrode assembly is independently and controlled to be turned on.

[0263] An electric field is created between the positive and negative electrodes due to a potential difference. Multiple negative electrodes are connected in series, and an electric field is formed between the positive and negative electrodes by supplying power to the positive electrode. This simplifies the wiring of the multiple negative electrodes. Furthermore, the interconnected negative electrodes have equal potentials, which allows for adjustment of the electric field strength by adjusting the voltage at the positive electrode.

[0264] Multiple positive electrodes are independently and controllably energized, allowing for simultaneous or sequential energization. This configuration enables the electrode assembly to perform various sorting methods.

[0265] Optionally, combined Figure 19 As shown, the electrode assembly also includes a first shielding electrode 870, which is disposed on the second side of the droplet channel 311 and is opposite to the electrode unit.

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

[0267] Optionally, the first shielding electrode 870 is connected to the negative electrode 820 of the electrode unit.

[0268] In this configuration, the negative electrode of the electrode unit is grounded, and the first shielding electrode is also grounded. This simplifies the wiring of the negative electrode and the first shielding electrode of the electrode assembly, thereby reducing the cost of the electrode assembly.

[0269] Optionally, combined Figure 19 , Figure 20 As shown, the electrode assembly also includes a second shielding electrode 880, which is disposed on the first side of the droplet flow channel and is disposed on the circumferential outer side of the electrode unit and surrounds the electrode unit.

[0270] A second shielding electrode is provided, and the electromagnetic effect generated by the positive electrode towards the first side of the first flow channel is confined within the second shielding electrode. This further reduces electromagnetic interference caused by the electric field between the positive and negative electrodes to the electronic components of the droplet sorting system.

[0271] Optionally, the second shielding electrode 880 is connected to the negative electrode 820 of the electrode unit.

[0272] In this configuration, the negative electrode of the electrode unit is grounded, and the second shielding electrode is also grounded. This simplifies the wiring of the negative electrode and the second shielding electrode of the electrode assembly, thereby reducing the cost of the electrode assembly.

[0273] The electrode assembly provided in this embodiment can provide a continuous and uniform pulling force to the target droplet, thereby allowing the droplet to pass through the droplet channel at a higher speed, which can significantly improve the droplet sorting throughput. By providing a pulling force to the target droplet through multiple positive electrodes of multiple electrode units or electrode assemblies, the pulling force on the target droplet is relatively gentle, and the droplet is not easily torn apart.

[0274] Optionally, the positive and / or negative electrodes of the electrode unit are connected to a power supply via a high-voltage isolation pulse transformer.

[0275] The high-voltage isolation pulse transformer provides high electrical isolation between its 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 enhances the safety of the droplet sorting system.

[0276] If multiple positive electrodes are energized, the target droplet is subjected to multiple electric fields as it flows through the electrode assembly, resulting in complex forces that make the droplet prone to tearing. By controlling the multiple positive electrodes to be energized one by one, the target droplet is subjected to only one or two electric fields within the same time period. This makes the deflection of the target droplet easier to control and reduces the likelihood of it tearing.

[0277] Optionally, combined Figures 16 to 21 As shown, the flow channel assembly includes a microfluidic chip, which internally defines a droplet flow channel 311, a first liquid outlet flow channel 314, and a second liquid outlet flow channel 315.

[0278] 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 allows for non-destructive droplet sorting, ensuring sample viability and integrity.

[0279] Optionally, the microfluidic chip further defines the sheath fluid inflow channel 312 and the sample fluid inflow channel 313. The inlet end of the sample fluid inflow channel 313 is used to fill the droplets that have passed through the pre-magnetized magnetic field. The outlet end of the sample fluid inflow channel 313 and the outlet end of the sheath fluid inflow channel 312 are connected to the inlet end of the droplet channel 311. The droplets that have passed through the pre-magnetized magnetic field are mixed with the sheath fluid and then enter the droplet channel 311.

[0280] The pre-magnetized droplets are water-in-oil droplets encapsulated in sheath fluid. However, the water-in-oil droplets serve to isolate the antibodies and antigens from interfering with each other between neighboring droplets. After the sample solution enters the flow channel 313 of the microfluidic chip 310, the water-in-oil droplet mixes again with the sheath fluid in the flow channel 312, allowing the droplet to flow within the droplet flow channel 311 at a preset flow rate and preset adjacent distance. This configuration facilitates the identification, observation, and sorting of samples within the droplets within the microfluidic chip 310.

[0281] Optionally, the microfluidic chip further defines a positive electrode channel and a negative electrode channel 317, wherein the positive electrode channel and the negative electrode channel 317 are filled with a conductive medium to form a positive electrode, and / or, the negative electrode channel 317 is filled with a conductive medium to form a negative electrode.

[0282] With this configuration, the positive electrode 810 and 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 negative electrode 820 are embedded within the microfluidic chip 310, reducing the risk of electrode short circuits or leakage in the droplet sorting system.

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

[0284] This configuration reduces the difficulty of processing and shaping the positive and negative electrodes, and lowers the cost of the droplet sorting system.

[0285] Optionally, the positive electrode channel is located on one side of the droplet channel 311, and the negative electrode channel 317 is located on the other side of the droplet channel 311.

[0286] Both the positive electrode channel and the negative electrode channel 317 are located on the plane of the microfluidic chip and are located on both sides of the droplet channel 311. When the target droplet is subjected to electrophoretic force, the deflection direction of the target droplet is in the same plane. This arrangement is beneficial for the target droplet to deflect under the action of electrophoretic force.

[0287] Optionally, the conductive medium is made of metal, and the metal conductive medium is filled into the positive electrode channel 316 in liquid form.

[0288] This configuration reduces the difficulty of forming the metal electrodes and lowers the cost of the droplet sorting system.

[0289] Optionally, if the electrode assembly also includes a first shielding electrode, the microfluidic control chip further defines a first shielding electrode channel 318, in which a conductive medium is filled to form a first shielding electrode, and the negative electrode channel is also connected to the first shielding electrode channel.

[0290] This allows the first shielding electrode to be integrated into the microfluidic chip, simplifying the structure of the sorting device and reducing its cost.

[0291] Optionally, if the electrode assembly also includes a second shielding electrode, the microfluidic control chip further defines a second shielding electrode channel 319, which is filled with a conductive medium to form a second shielding electrode, and the negative electrode channel is also connected to the second shielding electrode channel.

[0292] This allows the second shielding electrodes to be integrated into the microfluidic chip, simplifying the structure of the sorting device and reducing its cost.

[0293] Optionally, combined Figure 21 As shown, the microfluidic control chip also defines a connecting channel 3189. The first end of the connecting channel 3189 is connected to the first shielding electrode channel 318, and the 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 and the second shielding electrode channel.

[0294] With this configuration, multiple negative electrodes, the first shielding electrode, and the second shielding electrode can be connected using only one electrode connector, simplifying the connection structure of the negative electrodes, the first shielding electrode, and the second shielding electrode, and reducing the cost of the sorting device.

[0295] Optionally, combined Figure 15 As shown, the sorting device further 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 channel 316 of the microfluidic chip, and the negative electrode connector 832 is fixed to the electrode mounting plate 840 and extends to the negative electrode channel 317 of the microfluidic chip. The positive electrode connector 831 is used to electrically connect the positive electrode to a power source, and the negative electrode connector is used to electrically connect the negative electrode to a power source.

[0296] With this configuration, the positive and negative electrodes of the electrode assembly can be easily connected to or disconnected from the power supply. Furthermore, the tight connection via the electrode connectors prevents malfunctions caused by loose connections.

[0297] Combination Figure 22 As shown in the embodiments of this disclosure, a fluorescence signal detection method is provided to enhance the fluorescence signal of a droplet. The method includes:

[0298] S01, the fluorescence signal detection device pre-magnetizes the droplets to cause the magnetic particles in the droplets to agglomerate.

[0299] S02, the fluorescence signal detection device applies a magnetic field to the droplets to pull the aggregated magnetic particles into a thread.

[0300] S03, the fluorescence signal detection device applies a laser to the linear magnetic particles to make the fluorescent markers bound to the magnetic particles in the droplet emit light.

[0301] S04, The fluorescence signal detection device detects the fluorescence signal of the fluorescent marker in the droplet.

[0302] The fluorescence detection method provided in this disclosure can be used to identify samples such as cells, bacteria, and viruses. The droplet contains at least one cell, bacterium, or virus, and a fluorescently identifiable marker.

[0303] As one application method, the fluorescence signal enhancement method provided in this disclosure is applied to the following sample solution: the sample solution includes multiple droplets, each droplet including at least one cell, multiple magnetic particles, multiple antibodies specifically bound to the magnetic particles, and multiple antigens and / or secondary antibodies specifically bound to the antibodies, wherein at least one of the antigens and / or secondary antibodies is fluorescently stained.

[0304] In this embodiment, pre-magnetizing the droplets to cause the magnetic particles in the droplets to agglomerate can be performed by the pre-magnetizing 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 agglomerate the magnetic particles. Since incubation has ended, the magnetization of the magnetic particles does not affect the incubation effect.

[0305] In this embodiment, applying a magnetic field to the droplets can be accomplished in the aforementioned chip assembly or in other forms of flow cytometry cell sorting devices. In any sorting method, drawing the particle clusters composed of magnetic particles into a thread shape can improve the accuracy of fluorescent recognition of the droplets.

[0306] The fluorescence signal detection method provided in this disclosure can be implemented based on the fluorescence signal enhancement device, fluorescence signal detection device, or droplet observation device described above.

[0307] After pre-magnetizing the droplet, the magnetic particles within it are magnetized and aggregate. The aggregated magnetic particles are then drawn into a linear shape within the first magnetic field. Because the magnetic particles are linear, the antigens and / or secondary antibodies bound to them also exhibit a linear distribution. Applying laser light to the linear magnetic particles allows for more complete excitation of the antigens and / or secondary antibodies. When detecting the fluorescence signal of the fluorescent label, a distinct characteristic peak is observed. Thus, the characteristic peaks of the antigens and / or secondary antibodies allow for a more accurate determination of whether the droplet contains target cells.

[0308] Using the droplet sorting method provided in this embodiment, the pre-magnetization component can magnetize the magnetic particles before they enter the first magnetic field, thereby forming an aggregated state. The magnetized and aggregated magnetic particles can be better pulled into a linear shape after entering the magnetic field, so that the fluorescent material in the particle cluster can be more fully excited by the laser, thereby improving the droplet recognition accuracy.

[0309] Optionally, pre-magnetizing the droplet to cause the magnetic particles in the droplet to agglomerate includes: applying a pre-magnetizing magnetic field to the magnetic particles to magnetize the magnetic particles in the droplet; and repeatedly changing the direction and / or intensity of the pre-magnetizing magnetic field to promote the agglomeration of the magnetized magnetic particles in the droplet.

[0310] Magnetic particles in a droplet are not only magnetized in a pre-magnetizing magnetic field, but also rotate and move under the influence of magnetic force, thus agglomerating. Magnetic particles can be magnetized in a short time, but agglomeration takes a considerable amount of time. When the direction of the pre-magnetizing magnetic field changes, it intensifies the movement of the magnetic particles in the magnetic field, thereby accelerating their agglomeration. This method can improve the agglomeration effect of magnetic particles in a droplet within a pre-magnetizing magnetic field.

[0311] Optionally, changing the direction of the pre-magnetizing magnetic field multiple times includes: controlling the direction of the pre-magnetizing magnetic field to change over time; or, changing the angle of the droplet in the pre-magnetizing magnetic field multiple times.

[0312] One implementation involves a pre-magnetized magnet, such as an alternating current electromagnet. When energized, the pre-magnetized magnet generates a circumferential magnetic field. Another implementation involves droplets flowing in a pre-magnetized magnetic field, creating a flow path with changing direction. This facilitates the movement and aggregation of magnetic particles within the droplet within the pre-magnetized magnetic field.

[0313] Optionally, changing the strength of the pre-magnetizing magnetic field multiple times includes: controlling the strength of the pre-magnetizing magnetic field to change over time; or, changing the position of the droplet in the pre-magnetizing magnetic field multiple times.

[0314] One implementation involves a premagnetizing magnet, which includes an electromagnet. The strength of the premagnetizing magnetic field is altered by changing the current intensity of the electromagnet. Another implementation involves the droplet flowing within the premagnetizing magnetic field, occupying different positions within the field, thus varying the magnetic field strength acting on the droplet. This facilitates the movement and aggregation of magnetic particles within the droplet within the premagnetizing magnetic field.

[0315] Combination Figure 23 As shown in the embodiments of this disclosure, a droplet sorting method is provided, the method comprising:

[0316] S11, the droplet sorting system pre-magnetizes the droplets to cause the magnetic particles in the droplets to agglomerate.

[0317] S21, the droplet sorting system applies a magnetic field to droplets to pull agglomerated magnetic particles into a thread.

[0318] S31, the droplet sorting system applies a laser to linear magnetic particles to make the fluorescent markers bound to the magnetic particles in the droplets glow.

[0319] S41, the droplet sorting system marks droplets that meet the fluorescence conditions as target droplets.

[0320] S51, the droplet sorting system applies a deflection force to the target droplet to deflect the end of the target droplet to the target flow channel.

[0321] The fluorescence detection method provided in this disclosure can be used to identify samples such as cells, bacteria, and viruses. The droplet contains at least one cell, bacterium, or virus, and a fluorescently identifiable marker.

[0322] For example, the droplet sorting method provided in this disclosure is used to sort cells prepared into water-in-oil droplets. 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. At least one of the antigens and / or secondary antibodies is fluorescently stained.

[0323] In this embodiment, pre-magnetizing the droplets to cause the magnetic particles in the droplets to agglomerate can be performed by the pre-magnetizing 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 agglomerate the magnetic particles. Since incubation has ended, the magnetization of the magnetic particles does not affect the incubation effect.

[0324] In this embodiment, applying a magnetic field to the droplets can be accomplished in the aforementioned chip assembly, or in other forms of flow cytometry cell sorting devices. Pulling the particle clusters, which consist of magnetic particles, into a thread shape can improve the accuracy of fluorescence recognition of cells.

[0325] Using the droplet sorting method provided in this embodiment, the pre-magnetization component can magnetize the magnetic particles before they enter the first magnetic field, thereby forming an aggregated state. The magnetized and aggregated magnetic particles can be better pulled into a linear shape after entering the magnetic field, so that the fluorescent material in the particle cluster can be more fully excited by the laser, thereby improving the droplet recognition accuracy.

[0326] Optionally, applying a deflection force to the target droplet to deflect the end of the target droplet to the target flow channel includes: the droplet sorting system sequentially activating 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.

[0327] The sorting device includes positive and negative electrodes. There are multiple positive electrodes, which are spaced apart on one side of the droplet flow channel along the direction of the droplet flow channel. When the multiple positive electrodes are activated in sequence, they apply deflection forces to the target droplet multiple times, thereby deflecting the target droplet to the target flow channel, which is the first outlet flow channel mentioned above.

[0328] With this setup, the electrophoretic force acts on the droplets for a longer period of time, which can better deflect the droplets to the target flow channel.

[0329] Optionally, the target flow channel is connected to a first air pump, and applying a deflection force to the target droplet to deflect the end of the target droplet to the target flow channel includes: activating the first air pump to apply positive pressure to the target flow channel in the case of a non-target droplet pre-entering the target flow channel, so as to deflect the non-target droplet to the non-target flow channel.

[0330] When the first air pump is working, it applies positive pressure to the first liquid outlet channel. This creates a pressure difference between the first and second liquid outlet channels. Non-target droplets flowing through the outlet section of the droplet channel are deflected towards the second outlet channel due to this pressure difference. The air pump has a fast response speed, enabling high-speed droplet sorting. Furthermore, when positive pressure is applied to the first liquid outlet channel by the air pump, the droplets experience uniform force, reducing the risk of sample damage.

[0331] 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 end of the target droplet to the target flow channel includes: activating the second air pump to apply positive pressure to the non-target flow channel to deflect the target droplet to the target flow channel when the target droplet is about to enter the non-target flow channel.

[0332] When the second air pump operates, it applies positive pressure to the second liquid outlet channel. This creates a pressure difference between the first and second liquid outlet channels. When the target droplet flows through the outlet section of the droplet channel, it is deflected towards the first liquid outlet channel under the influence of the pressure difference. This also enables high-speed sorting of droplets and makes it less likely for the sample in the target droplet to be damaged when it is deflected.

[0333] Optionally, the droplet contains multiple antibodies specifically bound to magnetic particles, multiple antigens specifically bound to the antibodies, and multiple secondary antibodies specifically bound to the antibodies, with both the antigens and secondary antibodies being 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 droplet to emit light, including: applying a first laser and a second laser to the linear magnetic particles to cause the first and second fluorescent markers bound to the magnetic particles in the droplet to emit light; and marking droplets that meet the fluorescence conditions as target droplets includes: marking droplets whose first fluorescence signal meets the first condition and whose second fluorescence signal meets the second condition as target droplets.

[0334] After applying a first laser and a second laser to the droplet, the antibodies and antigens in the droplet are excited to emit a first fluorescence signal and a second fluorescence signal. If the intensity of both the first fluorescence signal and the second fluorescence signal meets a preset condition, the droplet is considered to contain a particle cluster of magnetic particles, antibodies, antigens, and secondary antibodies, and the droplet is then marked as the target droplet.

[0335] This setup can further improve the accuracy of droplet recognition.

[0336] Optionally, the second condition is determined based on the first condition.

[0337] The amounts of magnetic particle antigen and secondary antibody vary in different droplets. When there are fewer magnetic particles or antigens in the droplet cluster, the corresponding number of antibodies is considered to be lower. Therefore, setting a correspondingly lower second condition for the second fluorescence signal when the first fluorescence signal is weaker is beneficial for identifying more target droplets that meet the intended application.

[0338] Optionally, combined Figure 24 As shown, after marking droplets whose first fluorescence signal meets the first condition and whose second fluorescence signal meets the second condition as target droplets, the droplet sorting method further includes:

[0339] S61, the droplet sorting system acquires the first moment when the target droplet flows through the imaging position.

[0340] S71, the droplet sorting system activates the imaging component at the first moment to obtain an image of the target droplet.

[0341] This setup allows for the acquisition of images of target droplets during the droplet sorting process. This not only facilitates analysis and research of target droplets based on their images but also allows users to adjust parameters such as the pre-magnetizing magnetic field strength, the first magnetic field strength, and the droplet flow rate of the droplet sorting system based on the acquired images.

[0342] 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:

[0343] S81, the droplet sorting system activates the light source component at the first moment to provide supplemental light to the imaging component.

[0344] The light source component is activated only at the first moment, which can reduce light pollution from the light source component and extend its service life.

[0345] Combination Figure 25As shown, this disclosure provides a fluorescence signal detection device, including a processor 900 and a memory 901. Optionally, the device may further include a communication interface 902 and a bus 903. The processor 900, communication interface 902, and memory 901 can communicate with each other via the bus 903. The communication interface can be used for information transmission. The processor can call logical instructions in the memory to execute the fluorescence signal detection method of the above embodiment.

[0346] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0347] 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 this disclosure. The processor executes the program instructions / modules stored in the memory to perform functional applications and data processing, thereby implementing the droplet sorting method in the above embodiments.

[0348] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory may include high-speed random access memory and may also include non-volatile memory.

[0349] Combination Figures 1 to 21 As shown, this disclosure provides a droplet sorting system, including a droplet sorting system body and the aforementioned fluorescence signal detection device. The fluorescence signal detection device is installed on the product body. The installation relationship described herein 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. Those skilled in the art will understand that the droplet can be adapted to suitable product bodies to achieve other feasible embodiments.

[0350] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the fluorescence signal detection method described above.

[0351] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0352] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0353] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0354] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0355] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0356] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending 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 blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using 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: The pre-magnetizing component is used to generate a pre-magnetizing magnetic field, in which magnetic particles in the droplet are magnetized and aggregated. The magnetic particles are paramagnetic. A magnet assembly is used to generate a first magnetic field in which magnetic particles aggregated in the droplet are pulled into a thread shape. The magnetic field strength of the pre-magnetizing magnetic field is greater than the magnetic field strength of the first magnetic field; The pre-magnetization component includes: The pre-magnetized conduit defines a pre-magnetized flow path for droplet flow; A pre-magnetized magnet for generating a pre-magnetized magnetic field, at least a portion of the pre-magnetized flow channel being located within the pre-magnetized magnetic field; The pre-magnetizing magnetic field includes a first part and a second part. The direction of the magnetic field in the first part remains unchanged, while the direction of the magnetic field in the second part changes over time. The device also includes: A flow channel assembly defines a droplet flow channel, at least a portion of which is located in the first magnetic field, and the flux of the droplet flow channel is set to allow only one droplet to pass through at a time. The magnet assembly includes: A first magnet is disposed on one side of the droplet channel; A second magnet is disposed on the other side of the droplet channel; The length direction of the droplet channel is along the direction that cuts the magnetic field lines between the first magnet and the second magnet; A laser is applied to linear magnetic particles to cause fluorescent markers bound to the magnetic particles in a droplet to emit light; the fluorescence signal of the fluorescent markers in the droplet is detected.

2. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized magnet includes: A pre-magnetizing coil is wound around the pre-magnetizing conduit, the axis of the pre-magnetizing coil is along the length of the pre-magnetizing conduit, and the pre-magnetizing magnetic field is generated when the coil is energized.

3. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized magnet includes: A first pre-magnetized magnet is disposed on one side of the pre-magnetized pipeline; The second pre-magnetized magnet is located on the other side of the pre-magnetized pipeline.

4. 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 changing direction. When the magnetic particles in the droplet are in the pre-magnetized channel, they move and agglomerate under the action of the changing magnetic field force.

5. The fluorescence signal enhancement device according to claim 4, characterized in that, The pre-magnetized magnet includes multiple magnet pairs, which are arranged close to the pre-magnetized flow channel. Magnetic field lines are formed between each magnet pair, and the magnetic field lines of the multiple magnet pairs are in different directions to form a pre-magnetized magnetic field with varying directions.

6. The fluorescence signal enhancement device according to claim 4, characterized in that, The pre-magnetized magnet includes an electromagnet, and the direction of the current in the electromagnet is adjusted to form a pre-magnetized magnetic field with varying direction; or, The pre-magnetized magnet includes a coil wound around the pre-magnetized conduit. When the coil is energized, it generates the pre-magnetized magnetic field. The direction of the pre-magnetized magnetic field can be varied by adjusting the current intensity and / or current direction of the coil.

7. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized channel is a channel with changing direction, and at least a portion of the channel with changing direction is located in the pre-magnetized magnetic field. When the magnetic particles in the droplet move in the channel with changing direction, they are moved and aggregated by the force of the first magnetic field.

8. The fluorescence signal enhancement device according to claim 7, characterized in that, The pre-magnetized flow channel includes multiple bends, which are connected end to end to form a pre-magnetized flow channel with changing direction.

9. The fluorescence signal enhancement device according to claim 8, characterized in that, The pre-magnetized flow channel is a spiral flow channel.

10. The fluorescence signal enhancement device according to claim 9, characterized in that, The pre-magnetized conduit is wound around the pre-magnetized magnet to form the flow channel with the changing direction.

11. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized magnet includes an AC electromagnet, which forms the second part of the pre-magnetized magnetic field when energized.

12. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized magnet includes a DC electromagnet, and the DC electromagnet forms the first part of the pre-magnetized magnetic field when energized.

13. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized conduit is a flexible hose, and the length of the portion located in the pre-magnetized magnetic field can be adjusted by moving the pre-magnetized conduit.

14. The fluorescence signal enhancement device according to claim 1, characterized in that, The pre-magnetized channel is connected to the droplet channel, and the droplet channel is located after the pre-magnetized channel along the droplet flow direction.

15. The fluorescence signal enhancement device according to claim 1, characterized in that, The flow channel assembly includes: A microfluidic chip defines a chip channel for droplet flow. The chip channel includes a sheath fluid inflow channel, a sample fluid inflow channel, and a droplet channel. At least a portion of the droplet channel is located in a first magnetic field. The inlet end of the sample fluid inflow channel is used to fill droplets that have passed through a pre-magnetized magnetic field. The outlet ends of the sample fluid inflow channel and the outlet ends of the sheath fluid inflow channel are connected to the inlet end of the droplet channel. The droplets that have passed through the pre-magnetized magnetic field mix with the sheath fluid and then enter the droplet channel.

16. The fluorescence signal enhancement device according to claim 15, characterized in that, The flow channel assembly also includes: The supporting frame includes a base plate, a first side plate, and a second side plate, with the first side plate and the second side plate arranged opposite to each other; The microfluidic chip is located between the first side plate and the second side plate, and overlaps the upward-facing side of the base plate.

17. The fluorescence signal enhancement device according to claim 16, characterized in that, Also includes: The support plate has an installation window; A fixing component for securing the flow channel assembly to the mounting window.

18. The fluorescence signal enhancement device according to claim 17, characterized in that, The fixing component includes: The first clamping element is used to fix the first end of the chip assembly; The second clamp is used to secure the second end of the chip assembly.

19. The fluorescence signal enhancement device according to claim 18, characterized in that, The pre-magnetized component is fixed to the support plate.

20. The fluorescence signal enhancement device according to claim 16, characterized in that, The magnet assembly includes: The first magnet is disposed on the inward side of the first side plate; The second magnet is located on the inward side of the second side plate.

21. A fluorescence signal detection device, characterized in that, include: The fluorescence signal enhancement device according to any one of claims 1 to 20; and, A laser component is used to emit a laser beam toward magnetic particles that have been stretched into a wire shape, and fluorescent markers in the droplets are excited by the laser to emit fluorescence. A fluorescence detection component used to detect fluorescence emitted by fluorescent markers in droplets.

22. The fluorescence signal detection device according to claim 21, characterized in that, In the case where claim 21 refers to any one of claims 17 to 19 The laser component is disposed below the support plate, and its light emission direction is towards the portion of the droplet channel located in the first magnetic field; and / or, The fluorescence detection component is disposed below the support plate, and the detection direction is towards the part of the droplet channel located in the first magnetic field.

23. The fluorescence signal detection device according to claim 22, characterized in that, The base plate of the supporting frame has an observation window, and the microfluidic chip is made of transparent material at least in the first part of the observation window. 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.

24. A droplet observation device, characterized in that, Includes the fluorescence signal enhancement device according to any one of claims 1 to 20; and, The light source assembly emits light towards the droplet in the first magnetic field; The imaging component is positioned so that the imaging point is oriented towards the droplet in the first magnetic field.

25. The droplet observation device according to claim 24, characterized in that, Where claim 24 refers to any one of claims 17 to 19 The light source assembly is disposed above the support plate, and the light emission direction is towards the portion of the droplet channel located in the first magnetic field; and / or, The imaging component is disposed below the carrier plate and the light emission direction is towards the part of the droplet channel located in the first magnetic field.

26. The droplet observation device according to claim 24, characterized in that, The imaging component includes: A high-speed camera, wherein the light source assembly opens synchronously with the shutter of the high-speed camera.

27. The droplet observation device according to claim 24, characterized in that, The base plate of the supporting frame has an observation window. At least the first part of the microfluidic chip corresponding to the observation window is made of transparent material, and the imaging position of the imaging component faces the first part of the observation window.

28. The droplet observation device according to claim 27, characterized in that, The upward-facing side of the microfluidic chip, at least the second part corresponding to the observation window, is made of transparent material, and the light emitted by the light source assembly is directed toward the second part of the microfluidic chip.

29. A method for detecting fluorescence signals, comprising using the fluorescence signal detection device according to any one of claims 21 to 23 for detecting the fluorescence signal of a droplet, characterized in that, include: Pre-magnetize the droplets to cause the magnetic particles in the droplets to agglomerate; A magnetic field is applied to the droplets to pull the aggregated magnetic particles into a thread shape; Applying a laser to linear magnetic particles causes fluorescent markers bound to the magnetic particles in a droplet to glow; Detect the fluorescence signal of fluorescent markers in droplets.

30. The fluorescence signal detection method according to claim 29, characterized in that, Pre-magnetizing the droplets to cause the magnetic particles in the droplets to agglomerate includes: A pre-magnetizing magnetic field is applied to the magnetic particles to magnetize the magnetic particles in the droplet; The direction and / or intensity of the pre-magnetizing magnetic field are changed repeatedly to induce the aggregation of magnetized magnetic particles in the droplet.

31. The fluorescence signal detection method according to claim 30, characterized in that, Changing the direction of the pre-magnetizing magnetic field multiple times includes: Controlling the direction of the pre-magnetizing magnetic field to change over time; or, The angle of the droplet in the pre-magnetized magnetic field was changed multiple times.

32. The fluorescence signal detection method according to claim 30, characterized in that, The strength of the pre-magnetizing magnetic field was changed multiple times, including: Controlling the change in the strength of the pre-magnetizing magnetic field over time; or, The position of the droplet in the pre-magnetized magnetic field was changed multiple times.

Images