Microfluidic chip, cartridge device, microfluidic device

Abstract

The present disclosure provides a microfluidic chip, a cartridge device adapted to the microfluidic chip, and a microfluidic device comprising the microfluidic chip and the cartridge device. The microfluidic chip comprises a first holding portion holding a first fluid, a second holding portion holding a second fluid, a transport flow channel, a sorting flow channel, and a collection portion. The transport flow channel is shaped such that the first fluid and the second fluid meet at a meeting point. The sorting flow channel comprises a first sorting flow channel and a second sorting flow channel. The collection portion comprises a first collection portion and a second collection portion.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to PCT International Application No. PCT / CN2021 / 090291, filed on April 27, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of biomedical detection, and more particularly to a microfluidic chip, a housing device used in conjunction with the microfluidic chip, and a microfluidic device including the microfluidic chip and the housing device. Background Technology

[0004] Cells are the basic structural and functional units of living organisms. Due to the high heterogeneity among individual cells, the mean data obtained through cell population analysis essentially masks the differences between individual cells, thus failing to characterize the random nature of gene expression and reflecting the true situation. With the continuous development of life sciences and precision medicine, cell population analysis is gradually evolving towards single-cell analysis. A key technology in single-cell analysis is the ability to isolate individual cells from highly heterogeneous biological samples containing numerous cells. Single-cell sorting technology provides new options for popular medical fields such as single-cell analysis, early cancer diagnosis, and companion diagnostics. Summary of the Invention

[0005] According to one aspect of this disclosure, a microfluidic chip is provided. The microfluidic chip includes: a first receiving portion configured to receive a first fluid; a second receiving portion configured to receive a second fluid, the second fluid comprising a cell suspension; a delivery channel including a first delivery channel and a second delivery channel, the first delivery channel communicating with the first receiving portion and the second delivery channel communicating with the second receiving portion, the first delivery channel and the second delivery channel intersecting and communicating with each other at a confluence point, the shape of the delivery channel being designed such that the first fluid and the second fluid converge at the confluence point; a sorting channel located downstream of the delivery channel, the sorting channel including a first sorting channel and a second sorting channel; and a collecting portion located downstream of the sorting channel and including a first collecting portion and a second collecting portion, the first collecting portion communicating with the first sorting channel and the second collecting portion communicating with the second sorting channel.

[0006] In some embodiments, a portion of the first conveying channel is divided into a first segment and a second segment by the confluence point. In each of the first and second segments, the area of ​​a first cross-section of the segment gradually increases along a first direction away from the confluence point, the first cross-section being perpendicular to the first direction. Furthermore, the second conveying channel is divided into a third and a fourth segment by the confluence point. In each of the third and fourth segments, the area of ​​a second cross-section of the segment gradually increases along a second direction away from the confluence point, the second cross-section being perpendicular to the second direction.

[0007] In some embodiments, the beginning of the first sorting channel and the beginning of the second sorting channel are both connected to the end of the conveying channel. The end of the first sorting channel is connected to the first collection section and the end of the second sorting channel is connected to the second collection section. The first sorting channel and the second sorting channel bend from the end of the conveying channel toward the confluence point, and the first collection section and the second collection section are located between the confluence point and the end of the conveying channel.

[0008] In some embodiments, the sorting channel further includes at least two connecting channels. The second sorting channel includes at least two cascaded branches, and a connecting channel is provided between any two adjacent branches of the at least two cascaded branches, and the two adjacent branches are connected via the connecting channel; the beginning of the first sorting channel is connected to the end of the conveying channel, the end of the first sorting channel is connected to the first collection section, the first sorting channel is adjacent to a first-level branch of the at least two cascaded branches, and a connecting channel is provided between the first sorting channel and the first-level branch, and the first sorting channel and the first-level branch are connected via the connecting channel; and the second collection section includes at least two sub-collection sections, the cascaded branches correspond one-to-one with the sub-collection sections, and one of the cascaded branches is connected to a corresponding one of the sub-collection sections.

[0009] In some embodiments, the second sorting channel includes cascaded first-level branches, second-level branches, and third-level branches; the at least two connecting channels include a first connecting channel, a second connecting channel, and a third connecting channel; and the second collection section includes a first sub-collection section, a second sub-collection section, and a third sub-collection section. The first sorting channel is connected to the first-level branch via the first connecting channel; the first-level branch is connected to the second-level branch via the second connecting channel; and the second-level branch is connected to the third-level branch via the third connecting channel. Furthermore, the end of the first-level branch is connected to the first sub-collection section; the end of the second-level branch is connected to the second sub-collection section; and the end of the third-level branch is connected to the third sub-collection section.

[0010] In some embodiments, the second connecting channel is closer to the collection portion in a second direction than the first connecting channel, and the third connecting channel is closer to the collection portion in the second direction than the second connecting channel.

[0011] In some embodiments, the microfluidic chip further includes two third receptacles. The beginning of the first-level branch and the beginning of the second-level branch are respectively connected to one of the two third receptacles, and the third receptacles are configured to contain the first fluid.

[0012] In some embodiments, the sorting channel further includes at least two connecting channels. The first sorting channel includes at least two cascaded branches, and a connecting channel is provided between any two adjacent branches of the at least two cascaded branches, and the two adjacent branches are connected via the connecting channel. The ends of the at least two cascaded branches are all connected to the first collection section. The beginning of the second sorting channel is connected to the last-level branch of the first sorting channel via one of the connecting channels, and the end of the second sorting channel is connected to the second collection section.

[0013] In some embodiments, the sorting channel further includes a main channel, which is spiral-shaped in the plane of the microfluidic chip. The end of the main channel is connected to the first sorting channel and the second sorting channel. The first sorting channel is configured to screen a first droplet, and the second sorting channel is configured to screen a second droplet. The first droplet screened by the first sorting channel and the second droplet screened by the second sorting channel have different particle sizes.

[0014] In some embodiments, a portion of the first conveying channel includes a first sub-section, a second sub-section including the confluence point, and a third sub-section, wherein the first sub-section belongs to the first segment, the third sub-section belongs to the second segment, the second sub-section spans the first segment and the second segment and is located between the first sub-section and the third sub-section, and the area of ​​the first cross-section of both the first sub-section and the third sub-section is greater than the area of ​​the first cross-section of the second sub-section.

[0015] In some embodiments, the dimensions of the first cross-section of the second sub-section of the first delivery channel at the confluence point are configured to allow a first fluid with a specific particle size to flow within it, the specific particle size of the first fluid being larger than the particle size of a single cell in the cell suspension.

[0016] In some embodiments, the second conveying channel includes a first sub-channel, a second sub-channel, and a third sub-channel, wherein the first and second sub-channels belong to the third segment, and the third sub-channel belongs to the fourth segment. A first end of the first sub-channel communicates with the second receiving portion, a second end of the first sub-channel communicates with the first end of the second sub-channel, and a second end of the second sub-channel communicates with the first end of the third sub-channel, with both the second end of the second sub-channel and the first end of the third sub-channel located at the confluence point. The area of ​​the second cross-section of both the first and third sub-channels is larger than the area of ​​the second cross-section of the second sub-channel.

[0017] In some embodiments, the dimensions of the second cross-section of the second sub-channel are configured to allow a second fluid with a specific particle size to flow within it, the specific particle size of the second fluid being greater than 1 times the particle size of a single cell in the cell suspension and less than 2 times the particle size of the single cell.

[0018] In some embodiments, the area of ​​the second cross-section of the third sub-channel gradually increases along the direction from the first end to the second end of the third sub-channel.

[0019] In some embodiments, the area of ​​the first cross-section of the second sub-part of the first conveying channel at the confluence point is greater than or equal to the area of ​​the second cross-section of the second sub-channel and the third sub-channel of the second conveying channel at the confluence point.

[0020] In some embodiments, the inner wall surface of the conveying channel is hydrophobic.

[0021] In some embodiments, the outlines of the first receiving portion and the second receiving portion include four chamfers, the chamfers being arc-shaped.

[0022] In some embodiments, both the first and second accommodating portions are provided with a filtration structure, the filtration structure comprising a plurality of microstructures, wherein the gap between any two adjacent microstructures is greater than one times the particle size of a single cell in the cell suspension and less than two times the particle size of the single cell.

[0023] In some embodiments, the microfluidic chip further includes an inlet and an outlet. The inlet is disposed in the first and second accommodating portions, and the outlet is disposed in the collecting portion.

[0024] According to another aspect of this disclosure, a housing device is provided. This housing device is configured for use with a microfluidic chip described in any of the preceding embodiments, the microfluidic chip including an inlet and an outlet. The housing device includes: a receiving cavity configured to receive the microfluidic chip described in any of the preceding embodiments; an injection unit communicating with the inlet of the microfluidic chip, the injection unit being configured to store a first reagent and release the first reagent into the inlet of the microfluidic chip; and an outlet unit communicating with the outlet of the microfluidic chip, the outlet unit being configured to receive and store a second reagent processed by the microfluidic chip and flowing from the outlet of the microfluidic chip into the outlet unit. The injection unit includes an injection port and a first storage cavity, the injection port being a through-hole communicating with the first storage cavity, the injection port being recessed from the surface of the housing device into the interior of the housing device, and the first storage cavity being located on the side of the injection port away from the surface of the housing device.

[0025] In some embodiments, the first storage cavity is located inside the housing device, and the orthographic projection of the sample inlet on the housing device falls within the orthographic projection of the first storage cavity on the housing device.

[0026] In some embodiments, the sample injection unit further includes a second storage cavity located on the side of the first storage cavity away from the sample injection port and communicating with the first storage cavity. The second storage cavity includes a first opening communicating with the first storage cavity and a second opening opposite to the first opening. The orthographic projection of the second opening on the housing device falls within the orthographic projection of the first opening on the housing device.

[0027] In some embodiments, the orthographic projection of the second opening of the second storage cavity onto the housing device falls within the orthographic projection of the sample inlet onto the housing device.

[0028] In some embodiments, the sample dispensing unit includes a sample dispensing hole and a third storage cavity. The sample dispensing hole is a through hole and communicates with the third storage cavity. The sample dispensing hole is recessed from the surface of the housing device into the interior of the housing device, and the third storage cavity is located on the side of the sample dispensing hole away from the surface of the housing device.

[0029] In some embodiments, the third storage cavity is located inside the housing device, and the orthographic projection of the sample outlet on the housing device falls within the orthographic projection of the third storage cavity on the housing device.

[0030] In some embodiments, the sample dispensing unit further includes a fourth storage cavity, which is located on the side of the third storage cavity away from the sample dispensing orifice and communicates with the third storage cavity.

[0031] In some embodiments, the orthographic projection of the fourth storage cavity onto the housing device and the orthographic projection of the sample outlet onto the housing device may overlap by at most a portion.

[0032] In some embodiments, the orthographic projection of the fourth storage cavity onto the housing device falls within the orthographic projection of the sample outlet onto the housing device.

[0033] In some embodiments, the sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid, a cell suspension, and a biochemical reagent. The first sample introduction unit is connected to the first sample inlet of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first sample inlet of the microfluidic chip. The second sample introduction unit is connected to the second sample inlet of the microfluidic chip and is configured to store the cell suspension and release the cell suspension into the second sample inlet of the microfluidic chip. The third sample introduction unit is connected to the third sample inlet of the microfluidic chip and is configured to store the biochemical reagent and release the biochemical reagent into the third sample inlet of the microfluidic chip.

[0034] In some embodiments, the housing device further includes a first mounting region and a second mounting region, the first mounting region being configured to mount an optical recognition device and the second mounting region being configured to mount a driving electrode device.

[0035] In some embodiments, the sample introduction unit includes a first sample introduction unit and a second sample introduction unit, and the sample inlet of the microfluidic chip includes a first sample inlet and a second sample inlet. The first reagent includes a first fluid and a droplet comprising a single cell. The first sample introduction unit is connected to the first sample inlet of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first sample inlet of the microfluidic chip. The second sample introduction unit is connected to the second sample inlet of the microfluidic chip and is configured to store the droplet comprising a single cell and release the droplet comprising a single cell into the second sample inlet of the microfluidic chip. The sample dispensing unit includes a first sample dispensing unit, a second sample dispensing unit, and a third sample dispensing unit located between the first sample dispensing unit and the second sample dispensing unit. The second reagent includes a first droplet and a second droplet. The third sample dispensing unit is configured to receive and store the first droplet, and the first and second sample dispensing units are configured to receive and store the second droplet.

[0036] In some embodiments, the sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid, a cell suspension, and a biochemical reagent. The first sample introduction unit is connected to the first sample inlet of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first sample inlet of the microfluidic chip. The second sample introduction unit is connected to the second sample inlet of the microfluidic chip and is configured to store the cell suspension and release the cell suspension into the second sample inlet of the microfluidic chip. The third sample introduction unit is connected to the third sample inlet of the microfluidic chip and is configured to store the biochemical reagent and release the biochemical reagent into the third sample inlet of the microfluidic chip. The sample dispensing unit includes a first sample dispensing unit and a second sample dispensing unit. The second reagent includes a first droplet and a second droplet. The first sample dispensing unit is configured to receive and store the first droplet, and the second sample dispensing unit is configured to receive and store the second droplet.

[0037] In some embodiments, the first sample dispensing unit and the second sample dispensing unit are located between the sample injection unit and the first mounting area and the second mounting area.

[0038] In some embodiments, the first mounting area and the second mounting area are located between the sample injection unit and the sample dispensing unit. The first mounting area includes a first sub-mounting unit, a second sub-mounting unit, and a third sub-mounting unit. The second mounting area includes a fourth sub-mounting unit, a fifth sub-mounting unit, and a sixth sub-mounting unit. The first sub-mounting unit and the fourth sub-mounting unit are associated, the second sub-mounting unit and the fifth sub-mounting unit are associated, and the third sub-mounting unit and the sixth sub-mounting unit are associated.

[0039] In some embodiments, the sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid and a droplet comprising a single cell. The first sample introduction unit is connected to the first sample inlet of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first sample inlet of the microfluidic chip. The second sample introduction unit is connected to the second sample inlet of the microfluidic chip and is configured to store the first fluid and release the first fluid into the second sample inlet of the microfluidic chip. The third sample introduction unit is connected to the third sample inlet of the microfluidic chip and is configured to store the droplet comprising a single cell and release the droplet comprising a single cell into the third sample inlet of the microfluidic chip. The sample dispensing unit includes a first sample dispensing unit and a second sample dispensing unit. The second reagent includes a first droplet and a second droplet. The first sample dispensing unit is configured to receive and store the first droplet, and the second sample dispensing unit is configured to receive and store the second droplet.

[0040] In some embodiments, the number of the first sampling unit is one, and the number of the second sampling unit is three.

[0041] In some embodiments, the number of the first sampling unit is one, and the number of the second sampling unit is one.

[0042] In some embodiments, the cartridge device includes a sample inlet unit and two sample outlet units, the second reagent includes a first droplet and a second droplet, the first droplet and the second droplet having different particle sizes, one of the two sample outlet units is configured to receive and store the first droplet, and the other of the two sample outlet units is configured to receive and store the second droplet.

[0043] According to another aspect of this disclosure, a microfluidic device is provided, comprising a microfluidic chip as described in any of the preceding embodiments and a housing device as described in any of the preceding embodiments, the microfluidic chip being assembled with the housing device. Attached Figure Description

[0044] To more clearly describe the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1A A schematic diagram of the structure of a microfluidic chip according to an embodiment of the present disclosure is shown;

[0046] Figure 1B It shows Figure 1A A magnified schematic diagram of region I of the microfluidic chip;

[0047] Figure 1C It shows Figure 1A An enlarged schematic diagram of the housing of a microfluidic chip;

[0048] Figure 2 A schematic diagram of the structure of a microfluidic chip according to another embodiment of the present disclosure is shown;

[0049] Figure 3 It shows Figure 2 A schematic diagram of a variant of a microfluidic chip;

[0050] Figure 4 A schematic diagram of the structure of a microfluidic chip according to yet another embodiment of the present disclosure is shown;

[0051] Figure 5A A schematic diagram of the structure of a housing device according to an embodiment of the present disclosure is shown;

[0052] Figure 5B It shows Figure 5A A schematic diagram of the structure of the microfluidic chip adapted to the box-shaped device;

[0053] Figure 6A A schematic diagram of the structure of a housing device according to another embodiment of the present disclosure is shown;

[0054] Figure 6B It shows Figure 6A A schematic diagram of the structure of the microfluidic chip adapted to the box-shaped device;

[0055] Figure 7 A schematic diagram of the structure of a housing device according to yet another embodiment of the present disclosure is shown;

[0056] Figure 8 A schematic diagram of the structure of a housing device according to another embodiment of the present disclosure is shown;

[0057] Figure 9A schematic diagram of the structure of a housing device according to another embodiment of the present disclosure is shown; and

[0058] Figure 10 A block diagram of a microfluidic device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0059] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0060] Before formally describing the technical solutions of the embodiments of this disclosure, the terms used in the embodiments of this disclosure are explained and defined as follows to help those skilled in the art to more clearly understand the technical solutions of the embodiments of this disclosure.

[0061] As used herein, the term "fluid" refers to all substances capable of flowing, encompassing liquids and gases. A fluid is a substance capable of continuous deformation under minute shear forces. Fluids can consist of a single substance or a mixture of various substances. Fluids can be a continuous phase (e.g., oil), a dispersed phase (e.g., water), or a mixture of both. Fluids possess properties such as easy flowability, compressibility, and viscosity.

[0062] As used herein, the term "oil phase" refers to substances that are not readily soluble in water, according to the principle of "like dissolves like." For example, if a substance is miscible with water, and the resulting liquid separates into layers or becomes cloudy, then that substance is in the oil phase. Oils can have densities and / or viscosities higher or lower than water. Examples of oil phases include liquid paraffin, silicone oil, petrolatum, mineral oil, and perfluorinated oils.

[0063] As used herein, the term "aqueous phase" refers to substances that are readily soluble in water, according to the principle of "like dissolves like." For example, if a substance is miscible with water and the resulting liquid is a clear and homogeneous solution, then that substance is in the aqueous phase. Examples of substances in the aqueous phase include water, glycerol, alcohol, and acetone.

[0064] As used herein, the term "cell suspension" refers to a cell solution obtained by mechanical or chemical separation of cells from a tissue and dilution and mixing with cell culture medium. A cell suspension may contain a large number of cells, such as hundreds, thousands, tens of thousands, millions, or tens of millions of cells or more. The cells in a cell suspension may be of any type, including but not limited to prokaryotic cells, eukaryotic cells, bacteria, fungi, plant, mammalian or other animal cell types, mycoplasma, normal tissue cells, tumor cells, or any other cell type, whether or not derived from a single-celled or multicellular organism. Cells in a cell suspension may include DNA, RNA, organelles, proteins, or any combination thereof.

[0065] As used herein, the term "A connected to B" means that component A and component B are interconnected and communicate with each other, allowing fluid to flow between component A and component B. That is, fluid can flow from component A to component B, or from component B to component A, as required by product design. Component A and component B can be directly connected, meaning that fluid can flow directly from component A to component B or directly from component B to component A without passing through other intermediate components (e.g., pipes). Alternatively, component A and component B can be indirectly connected, meaning that fluid can flow from component A to component B via one or more intermediate components (e.g., pipes) or from component B to component A via one or more intermediate components (e.g., pipes).

[0066] As used herein, the term "polymerase chain reaction (PCR)" is a molecular biology technique used to amplify specific deoxyribonucleic acid (DNA) fragments. It can be viewed as a special form of DNA replication outside of a living organism, capable of replicating minute amounts of DNA in large quantities, significantly increasing its number. The basic principle of PCR is that DNA denatures and breaks down into single strands at high temperatures (e.g., around 95°C). When the temperature drops to low temperatures (e.g., around 60°C), primers bind to the single strands according to the base-complementary pairing principle, transforming them back into double strands. Therefore, by controlling the denaturation and renaturation of DNA through temperature changes and adding designed primers, large-scale DNA replication can be achieved. PCR reactions include, but are not limited to, digital PCR (dPCR), quantitative PCR, and real-time PCR. dPCR technology provides quantitative analysis of digital DNA information; when combined with microfluidic technology, it can offer higher sensitivity and accuracy.

[0067] As used herein, the term "microfluidic chip" refers to a chip with microchannels at the micrometer scale. This chip integrates basic operational units involved in sample preparation, reaction, separation, and detection in fields such as biology, chemistry, and medicine, automating the entire reaction and analysis process. Microfluidic chip-based analytical devices offer advantages such as controllable liquid flow, low sample consumption, fast detection speed, ease of operation, multifunctional integration, small size, and portability.

[0068] As used herein, the term "particle size of XX" refers to the size of substance XX, that is, the length of substance XX in a certain direction. Substance XX can be a single cell or a single droplet. For example, when the cell or droplet is spherical, the term "particle size of a single cell" refers to the diameter of a single cell, and "particle size of a single droplet" refers to the diameter of a single droplet. When the cell or droplet is rod-shaped, the term "particle size of a single cell" refers to the length of a single cell along its shorter side, and "particle size of a single droplet" refers to the length of a single droplet along its shorter side.

[0069] The inventors of this application have discovered that conventional techniques for sorting single cells mainly fall into two categories: one is the automatic sorting of single cells using a fluorescence-activated cell sorting (FACS) instrument, but this FACS instrument is expensive and has high maintenance costs; the other is the manual sorting of single cells by professional operators, but this manual sorting method not only depends on the operator's skill and proficiency but also requires large or medium-sized instruments such as micropipette platforms and optical tweezers. Furthermore, the single-cell sorting process is highly susceptible to contamination from airborne aerosols and microorganisms, which are usually difficult to remove in subsequent detection stages. Therefore, existing single-cell sorting methods suffer from drawbacks such as high cost, high operator skill requirements, space-limited equipment requirements, and susceptibility to environmental contamination.

[0070] In view of this, embodiments of the present disclosure provide a microfluidic chip. This microfluidic chip can be used to prepare droplets containing single cells derived from a cell suspension and to sort target droplets from the prepared droplets. This microfluidic chip enables the preparation and sorting of single cells, effectively improving automation while reducing operating costs, eliminating cross-contamination, and increasing cell viability.

[0071] Figure 1A A schematic diagram of the microfluidic chip 300 is shown, where (a) is a front view of the microfluidic chip 300, (b) is a rear view of the microfluidic chip 300, (c) is a left view of the microfluidic chip 300, and (d) is an axial view of the microfluidic chip 300. Figure 1AAs shown, the microfluidic chip 300 includes: a first receiving portion 301, a second receiving portion 302, a delivery channel 303, a sorting channel 305, and a collection portion 306. The first receiving portion 301 is configured to receive a first fluid, and the second receiving portion 302 is configured to receive a second fluid, the second fluid including a cell suspension. The delivery channel 303 includes a first delivery channel 3031 and a second delivery channel 3032. The first delivery channel 3031 communicates with the first receiving portion 301, and the second delivery channel 3032 communicates with the second receiving portion 302. The first delivery channel 3031 and the second delivery channel 3032 intersect and communicate with each other at a confluence point 304. The shape of the delivery channel 303 is designed such that the first fluid and the second fluid converge at the confluence point 304. The sorting channel 305 is located downstream of the delivery channel 303, and the sorting channel 305 includes a first sorting channel 3051 and a second sorting channel 3052. The collection section 306 is located downstream of the sorting channel 305 and includes a first collection section 3061 and a second collection section 3062. The first collection section 3061 is connected to the first sorting channel 3051, and the second collection section 3062 is connected to the second sorting channel 3052.

[0072] In some embodiments, the first sorting channel 3051 may be configured to sort a first droplet, and the second sorting channel 3052 may be configured to sort a second droplet. In such a case, the first collecting section 3061 is configured to collect the first droplet, and the second collecting section 3062 is configured to collect the second droplet.

[0073] It should be noted that in this paper, the term "first droplet" can refer to a non-target droplet, and the term "second droplet" can refer to a target droplet. A non-target droplet means that the droplet contains non-target cells from the cell suspension, while a target droplet means that the droplet contains a single target cell from the cell suspension. The cell suspension contains a large number of cells, including a majority of non-target cells and a small number of target cells (e.g., circulating tumor cells, rare cells, cancer cells, etc. in peripheral blood samples). In this paper, the terms "first droplet" and "non-target droplet" are used interchangeably, as are the terms "second droplet" and "target droplet."

[0074] This microfluidic chip 300 can not only prepare droplets containing single cells (single target cells or single non-target cells) from cell suspensions, but also sort out target droplets containing single target cells from these droplets. Therefore, the microfluidic chip 300 has a high degree of integration, automatically completing the preparation and sorting of droplets containing single cells without manual operation, thus effectively improving the automation level of the operation. Furthermore, since the first and second fluids flow only within the delivery channel 303, completely isolated from the external environment, contamination from airborne aerosols, microorganisms, etc., can be avoided. Moreover, because the single cells separated from the cell suspension are encapsulated and protected by the droplets, the entire preparation process is relatively gentle, thereby effectively improving cell survival rate.

[0075] The following describes in detail how to prepare droplets containing single cells using this microfluidic chip 300.

[0076] Figure 1B yes Figure 1A A magnified view of region I of the microfluidic chip 300. (Reference) Figure 1A and Figure 1B The microfluidic chip 300 has a delivery channel 303 including a first delivery channel 3031 and a second delivery channel 3032. The first delivery channel 3031 communicates with a first receiving portion 301 and allows a first fluid to flow within it. The first fluid is a continuous phase (e.g., an oil phase) liquid, which may be, for example, mineral oil, perfluorinated oil, or any suitable fluid. Optionally, a surfactant may be mixed into the first fluid, which helps to stabilize the resulting droplets, for example, by inhibiting subsequent aggregation of the resulting droplets. When the first fluid is a perfluorinated oil, the surfactant may be a perfluorinated surfactant. The second delivery channel 3032 communicates with a second receiving portion 302 and allows a second fluid to flow within it. The second fluid is an aqueous phase liquid. In the example shown in the figure, the second receiving portion 302 includes a first sub-receiving portion 3021 and a second sub-receiving portion 3022, where the first sub-receiving portion 3021 is configured to receive a cell suspension and the second sub-receiving portion 3022 is configured to receive biochemical reagents. Different biochemical reagents can be used depending on the different biochemical reactions. The embodiments disclosed herein do not specifically limit the chemical composition of the biochemical reagents. It should be noted that, although... Figure 1A The illustration shows a cell suspension contained in a first sub-receptacle 3021, and biochemical reagents contained in a second sub-receptacle 3022 separate from the first sub-receptacle 3021; ​​however, this is merely an example, and the embodiments of this disclosure are not limited thereto. In alternative embodiments, the cell suspension and biochemical reagents may be pre-mixed and contained in the same receptacle. The first delivery channel 3031 and the second delivery channel 3032 intersect and communicate at a confluence point 304.

[0077] A portion of the first conveying channel 3031 is divided into a first segment and a second segment by a confluence point 304. In each of the first and second segments, the area of ​​the first cross-section of that segment gradually increases along a first direction away from the confluence point 304. The first cross-section is perpendicular to the first direction, which is the vertical direction shown in the figure. The second conveying channel 3032 is divided into a third segment and a fourth segment by the confluence point 304. In each of the third and fourth segments, the area of ​​the second cross-section of that segment gradually increases along a second direction away from the confluence point 304. The second cross-section is perpendicular to the second direction, which refers to the flow direction of the second fluid within the second conveying channel 3032.

[0078] Specifically, the first conveying channel 3031 includes a first sub-section 3031-1, a second sub-section 3031-2, and a third sub-section 3031-3 arranged sequentially along a first direction. The second sub-section 3031-2 is located between the first sub-section 3031-1 and the third sub-section 3031-3 and includes a confluence point 304. The first sub-section 3031-1 belongs to the first segment described above, and the third sub-section 3031-3 belongs to the second segment described above. The second sub-section 3031-2 spans both the first and second segments. The area of ​​the first cross-section of the first sub-part 3031-1 and the third sub-part 3031-3 is larger than the area of ​​the first cross-section of the second sub-part 3031-2. That is, along the direction from the first sub-part 3031-1 to the third sub-part 3031-3, the first conveying channel 3031 gradually becomes thinner and then thicker, so that the first conveying channel 3031 has a shape that is thick at the top and bottom (first sub-part 3031-1 and third sub-part 3031-3) and thin in the middle (second sub-part 3031-2). With this shape design, when the first fluid in the first conveying channel 3031 flows from the first sub-section 3031-1 to the second sub-section 3031-2, or from the third sub-section 3031-3 to the second sub-section 3031-2, the flow velocity of the first fluid in the first conveying channel 3031 increases due to the narrowing of the channel. This increases the pressure of the first fluid, promoting its flow towards the confluence point 304 of the second sub-section 3031-2, where it converges. This provides sufficient first fluid for subsequent droplet formation. The shape of the first cross-section of the first sub-sections 3031-1, 3031-2, and 3031-3 of the first conveying channel 3031 can be circular, square, rectangular, regular polygonal, irregular, etc., and the embodiments of this disclosure do not limit this.

[0079] The dimensions of the first cross-section of the second sub-portion 3031-2 of the first transport channel 3031 at the confluence point 304 are configured to allow the flow of a first fluid with a specific particle size greater than the particle size of a single cell (e.g., a single target cell). That is, the width of the first cross-section of the second sub-portion 3031-2 of the first transport channel 3031 at the confluence point 304 is greater than the particle size of a single cell. In one example, the particle size of each cell in the cell suspension is approximately 10 μm, and the width of the cross-section of the second sub-portion 3031-2 of the first transport channel 3031 at the confluence point 304 is greater than 10 μm, for example, slightly greater than 10 μm. Here, "slightly greater than 10 μm" means that the width of the first cross-section of the second sub-portion 3031-2 of the first transport channel 3031 at the confluence point 304 is greater than 10 μm but less than 20 μm, i.e., this width is greater than the particle size of a single cell but less than the sum of the particle sizes of two cells. It should be noted that the phrase "the width of the first cross-section of the second sub-part 3031-2 of the first conveying channel 3031 at the confluence point 304" can be understood as follows: when the shape of the first cross-section of the second sub-part 3031-2 of the first conveying channel 3031 at the confluence point 304 is circular, the width of the first cross-section is the diameter of the circle; when the shape of the first cross-section of the second sub-part 3031-2 of the first conveying channel 3031 at the confluence point 304 is square, the width of the first cross-section is the side length of the square; when the shape of the first cross-section of the second sub-part 3031-2 of the first conveying channel 3031 at the confluence point 304 is rectangular, the width of the first cross-section is the length of the shorter side of the rectangle; and when the shape of the first cross-section of the second sub-part 3031-2 of the first conveying channel 3031 at the confluence point 304 is a regular polygon, the width of the first cross-section is the distance between the two farthest vertices of the regular polygon. In one example, when the first cross-section of the second sub-section 3031-2 of the first transport channel 3031 at the confluence point 304 is circular and the shape of the individual cells is spherical, then the width of the first cross-section of the second sub-section 3031-2 at the confluence point 304 being greater than the particle size of the individual cells should be understood as the diameter of the second sub-section 3031-2 at the confluence point 304 being greater than the diameter of the individual cells. With this design, when the first fluid in the first transport channel 3031 flows from the first sub-section 3031-1 to the second sub-section 3031-2, or from the third sub-section 3031-3 to the second sub-section 3031-2, the first fluid can form a single row of sequentially arranged fluid particles near the confluence point 304. The particle size of each particle in this single row is greater than one times the particle size of the individual cells and less than twice the particle size of the individual cells.This design allows each particle formed by the first fluid to have a slightly larger diameter than a single cell, thus better encapsulating the cell and achieving a better encapsulation effect. Furthermore, this design increases the flow velocity of the first fluid at the confluence point 304, which is beneficial for droplet formation.

[0080] The second conveying channel 3032 includes a first sub-channel 3032-1, a second sub-channel 3032-2, and a third sub-channel 3032-3. The first sub-channel 3032-1 and the second sub-channel 3032-2 belong to the third section described above, and the third sub-channel 3032-3 belongs to the fourth section described above. The first end of the first sub-channel 3032-1 is connected to the second receiving portion 302, and the second end of the first sub-channel 3032-1 is connected to the first end of the second sub-channel 3032-2; the second end of the second sub-channel 3032-2 is connected to the first end of the third sub-channel 3032-3, and both the second end of the second sub-channel 3032-2 and the first end of the third sub-channel 3032-3 are located at the confluence point 304; the second end of the third sub-channel 3032-3 is connected to the beginning of the sorting channel 305. The first sub-channel 3032-1 includes a first branch and a second branch. The first branch communicates with the first sub-receptacle 3021 of the second receptacle 302 and is configured to allow cell suspension to flow within it. The second branch communicates with the second sub-receptacle 3022 of the second receptacle 302 and is configured to allow biochemical reagents to flow within it. Figure 1B As shown, the first branch and the second branch intersect and connect at a single point, and the angle between them at that point is acute. In one example, the angle between the first branch and the second branch at that point is approximately 60 degrees. This angled design of the first and second branches ensures, on the one hand, that the cell suspension in the first branch and the biochemical reagents in the second branch have sufficient forward flow velocity (towards the confluence point 304) to buffer pressure; on the other hand, it ensures that the cell suspension and biochemical reagents can be fully mixed at that point; furthermore, it reduces the dead volume of the mixed solution in the flow channel, improving the liquid storage accuracy of the first and second branches.

[0081] The areas of the second cross-sections of the first sub-channel 3032-1 and the third sub-channel 3032-3 of the second conveying channel 3032 are both larger than the area of ​​the second cross-section of the second sub-channel 3032-2. That is, the areas of the second cross-sections of the first branch and the second branch of the first sub-channel 3032-1 are both larger than the area of ​​the second cross-section of the second sub-channel 3032-2, and the area of ​​the second cross-section of the third sub-channel 3032-3 is larger than the area of ​​the second cross-section of the second sub-channel 3032-2. Along the direction from the first sub-channel 3032-1 to the third sub-channel 3032-3, the second conveying channel 3032 gradually becomes wider and then narrower. Similar to the first conveying channel 3031, the shape of the second cross-section of the first sub-channel 3032-1, the second sub-channel 3032-2, and the third sub-channel 3032-3 of the second conveying channel 3032 can be circular, square, rectangular, regular polygonal, irregular, etc., and the embodiments disclosed herein do not limit this.

[0082] The dimensions of the second cross-section of the second sub-channel 3032-2 of the second delivery channel 3032 are configured to allow a second fluid with a specific particle size to flow within it, the specific particle size of the second fluid being greater than one time the particle size of a single cell and less than twice the particle size of a single cell. That is, the width of the second cross-section of the second sub-channel 3032-2 is greater than one time the particle size of a single cell and less than twice the particle size of a single cell. In one example, when the second cross-section of the second sub-channel 3032-2 is circular and the shape of the single cell is spherical, then the width of the second cross-section of the second sub-channel 3032-2 being greater than one time the particle size of a single cell and less than twice the particle size of a single cell should be understood as the diameter of the second sub-channel 3032-2 being greater than one time the diameter of a single cell and less than twice the diameter of a single cell. In this case, the diameter of the second sub-channel 3032-2 can be 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, etc., the diameter of the single cell. When the cell suspension and biochemical reagents are mixed and flow forward (towards the confluence point 304), the width of the second cross-section of the second sub-channel 3032-2 is greater than 1 times and less than 2 times the particle size of a single cell, causing the mixed solution to arrange into a single row of single cells within the second sub-channel 3032-2, such as... Figure 1BAs shown. That is, the width of the second cross-section of the second sub-channel 3032-2 only allows a single cell to be accommodated in its width direction, and cannot accommodate two cells side by side. When the single-cell string moves to the confluence point 304, under the pressure of the first fluid in the first delivery channel 3031, the cell closest to the confluence point 304 (i.e., the foremost cell in the cell string) separates from the cell string. This separated cell combines with a single particle in the first fluid at the confluence point 304, thereby forming a droplet containing a single cell. As mentioned earlier, the first fluid is an oil phase, and the second fluid (i.e., a mixture of cell suspension and biochemical reagents) is an aqueous phase. Therefore, the formed droplet has a water-in-oil structure, that is, the oil phase of the first fluid surrounds the aqueous phase of the second fluid.

[0083] As shown in the figure, the area of ​​the second cross-section of the third sub-channel 3032-3 of the second transport channel 3032 gradually increases from its first end to its second end; that is, the third sub-channel 3032-3 gradually thickens from its first end to its second end. This design aims to make the prepared droplets gradually increase in size as they move forward along the third sub-channel 3032-3, thereby facilitating droplet phase stabilization. The area of ​​the first cross-section of the second sub-part 3031-2 of the first transport channel 3031 at the confluence point 304 is greater than or equal to the area of ​​the second cross-section of the second sub-channel 3032-2 and the third sub-channel 3032-3 of the second transport channel 3032 at the confluence point 304. In one example, the area of ​​the first cross-section of the second sub-part 3031-2 of the first transport channel 3031 at the confluence point 304 is equal to the area of ​​the second cross-section of the second sub-channel 3032-2 and the third sub-channel 3032-3 of the second transport channel 3032 at the confluence point 304. This design allows the particle size of a single oil phase particle in the first fluid to be approximately equal to the particle size of a single cell in the second fluid at the confluence point 304, thus enabling precise control over the size of the formed droplets.

[0084] The above describes in detail how to prepare droplets containing single cells using the microfluidic chip 300. Below, we will detail how to use the microfluidic chip 300 to sort out the target droplets, i.e., droplets containing single target cells, from the prepared droplets.

[0085] The microfluidic chip 300 may also include an optical recognition device and a driving electrode device (not shown in the figure), which may be located near the third sub-channel 3032-3 of the second delivery channel 3032. Droplets generated at the confluence point 304 flow forward along the third sub-channel 3032-3, which is connected to the downstream sorting channel 305. As previously mentioned, the cell suspension contains a large number of cells, including a large number of non-target cells and a small number of target cells (e.g., circulating tumor cells, rare cells, cancer cells, etc. in peripheral blood samples). The cell suspension has been stained before being injected into the first sub-receptor 3021. Because the target cells and non-target cells in the cell suspension contain different antibodies, after fluorescent staining, these target cells and non-target cells will display different colors under the optical recognition device. Therefore, droplets can be roughly divided into the following three categories: (a) droplets containing a single target cell with the target color; (b) droplets containing non-target cells (including droplets containing one or more non-target cells and droplets containing multiple target cells); or (c) droplets containing no cells. As the droplet moves forward along the third sub-channel 3032-3, the optical recognition device detects the optical signal (e.g., color) of the droplet in the third sub-channel 3032-3 in real time. When the optical recognition device detects that the droplet is in the above-mentioned category (b) or (c), it will not notify the circuit system. Therefore, the circuit system will not apply voltage to the driving electrode, and the non-target droplet flows into the first sorting channel 3051 under the action of inertial force, and then flows into the first collection section 3061. In an alternative embodiment, when the optical recognition device detects a droplet in condition (b) or (c) above, it can also notify the circuit system. Upon receiving the notification, the circuit system applies a certain voltage to the driving electrode. The non-target droplet flows into the first sorting channel 3051 under the drive of the dielectric force, and then flows into the first collection section 3061. When the optical recognition device detects a droplet in condition (a) above, it immediately notifies the circuit system to apply an appropriate voltage (e.g., 800~1000V) to the driving electrode. The target droplet containing a single target cell is polarized. Under the action of the electric field, the target droplet deflects upward and flows into the second sorting channel 3052, and then into the second collection section 3062. Thus, the microfluidic chip 300 achieves droplet sorting, with non-target droplets collected in the first collection section 3061 and target droplets collected in the second collection section 3062.

[0086] It should be noted that the staining treatment of cell suspension is only one example of the embodiments of this disclosure. The treatment method of cell suspension is not limited to this. Any treatment method that can distinguish the target cells and non-target cells in the cell suspension is within the protection scope of this disclosure.

[0087] It should be noted that, although Figure 1A The sorting channel 305 is shown to include two sorting channels 3051 and 3052, but the embodiments of this disclosure are not limited thereto. In alternative embodiments, the sorting channel 305 may also include more channels (e.g., three channels, four channels, or more), one of which is configured to filter out non-target droplets from the droplets, and the remaining channels are configured to filter out target droplets from the droplets. Accordingly, the collection unit 306 may include a plurality of collection units, each corresponding one-to-one with a channel of the sorting channel 305. One of the collection units is connected to one of the channels of the sorting channel 305 and configured to collect non-target droplets, while the remaining collection units are connected to the remaining channels of the sorting channel 305 and configured to collect target droplets.

[0088] Continue to refer to Figure 1A The beginnings of the first sorting channel 3051 and the second sorting channel 3052 are both connected to the end of the conveying channel 303 (i.e., the end of the third sub-channel 3032-3 of the conveying channel 303). The end of the first sorting channel 3051 is connected to the first collection section 3061, and the end of the second sorting channel 3052 is connected to the second collection section 3062. The first sorting channel 3051 and the second sorting channel 3052 bend from the end of the conveying channel 303 toward the confluence point 304, thereby placing the first collection section 3061 and the second collection section 3062 between the confluence point 304 and the end of the conveying channel 303. Compared to the first sorting channel 3051 and the second sorting channel 3052 extending straight in the horizontal direction (i.e., the first sorting channel 3051 and the second sorting channel 3052 extending straight to the right in the figure), which connects the first collection part 3061 and the second collection part 3062 to their respective ends, by making the first sorting channel 3051 and the second sorting channel 3052 fold back from the end of the conveying channel 303 toward the confluence point 304, the volume occupied by the microfluidic chip 300 can be reduced, making the microfluidic chip 300 more miniaturized and saving production costs.

[0089] It should be noted that, in this document, the term "end of conveying channel 303" refers to the end of the third sub-channel 3032-3 of conveying channel 303, that is, the end of the third sub-channel 3032-3 of conveying channel 303, which is directly connected to the downstream sorting channel 305. The terms "beginning of the first sorting channel 3051 and beginning of the second sorting channel 3052" refer to the first end of the first sorting channel 3051 and the first end of the second sorting channel 3052. The first ends of the first sorting channel 3051 and the second sorting channel 3052 are directly connected to the end of the third sub-channel 3032-3 of the upstream conveying channel 303, and droplets flow from the end of the third sub-channel 3032-3 into the first end of the first sorting channel 3051 and the first end of the second sorting channel 3052, respectively. The terms "the end of the first sorting channel 3051 and the end of the second sorting channel 3052" refer to the second end of the first sorting channel 3051 and the second end of the second sorting channel 3052. The second end of the first sorting channel 3051 is connected to the first collection section 3061, and the second end of the second sorting channel 3052 is connected to the second collection section 3062. Non-target droplets flow from the first end of the first sorting channel 3051 to the second end of the first sorting channel 3051, and then flow into the first collection section 3061; target droplets flow from the first end of the second sorting channel 3052 to the second end of the second sorting channel 3052, and then flow into the second collection section 3062.

[0090] In some embodiments, the inner wall surface of the transport channel 303 is hydrophobically treated, thus possessing hydrophobicity. As previously described, the transport channel 303 includes a first transport channel 3031 configured for the flow of a first fluid and a second transport channel 3032 configured for the flow of a second fluid. The hydrophobically treated first transport channel 3031 facilitates the flow of the first fluid within it. The hydrophobically treated second transport channel 3032 promotes the smooth flow of the cell suspension within the first branch of the first sub-channel 3032-1 of the second transport channel 3032 without adhering to the inner wall surface, and also promotes the smooth flow of the mixture of cell suspension and biochemical reagent within the second sub-channels 3032-2 and 3032-3 of the second transport channel 3032 without adhering to the inner wall surface. This allows for precise control of the amount of cell suspension used, facilitating uniform mixing of the cell suspension and biochemical reagent, thereby promoting uniform droplet formation. Simultaneously, this also improves the utilization rate of the cell suspension and avoids waste.

[0091] exist Figure 1AIn the microfluidic chip 300 shown, the first receiving portion 301 further includes an inlet, through which an external device (such as the housing device described below) is connected to and injects a first fluid into the first receiving portion 301. The first sub-receiving portion 3021 of the second receiving portion 302 includes an inlet, through which an external device (such as the housing device described below) is connected to and injects a cell suspension into the first sub-receiving portion 3021. The second sub-receiving portion 3022 of the second receiving portion 302 includes an inlet, through which an external device (such as the housing device described below) is connected to and injects biochemical reaction reagents into the second sub-receiving portion 3022. The first collecting portion 3061 and the second collecting portion 3062 each include an outlet, which is used to connect to an external device (such as the housing device described below) to deliver droplets from the first collecting portion 3061 and the second collecting portion 3062 to the external device.

[0092] Figure 1C yes Figure 1A An enlarged schematic diagram of any one of the first sub-receiving portion 3021 and the second sub-receiving portion 302 of the first receiving portion 301 and the second receiving portion 302. (See diagram below.) Figure 1C As shown, the outlines of the first receiving portion 301 and the first sub-receiving portion 3021 and the second sub-receiving portion 3022 of the second receiving portion 302 both include four chamfers. The shape of the four chamfers can be any suitable shape, such as an arc. It should be understood that the specific dimensions of the chamfers are not limited in the embodiments of this disclosure. Taking the first sub-receiving portion 3021 of the second receiving portion 302 as an example, as... Figure 1CAs shown, the outline of the first sub-receptacle 3021 includes four chamfers 313, which are rounded. This rounded chamfer design reduces the dead volume of the cell suspension within the first sub-receptacle 3021, improving its storage accuracy. Here, "dead volume" refers to the uncontrollable volume during reagent introduction. Specifically, if the four corners of the first sub-receptacle 3021 were right angles instead of rounded chamfers, due to the surface tension of the droplets, the cell suspension would not be perfectly right-angled at the four right angles of the first sub-receptacle 3021. That is, the cell suspension would not perfectly match the shape of the first sub-receptacle 3021 and would not fill the space occupied by the four right angles. Therefore, the shape and volume of the cell suspension would change, and this change in shape and volume would have a certain degree of randomness, thus introducing dead volume. This could lead to the first sub-receptacle 3021 of the microfluidic chip 300 containing a different volume of cell suspension in each operation compared to the previous operation, resulting in an inability to precisely control the amount of cell suspension used. However, in the embodiments of this disclosure, the four corners 313 of the first sub-receptacle 3021 are designed as rounded chamfers, which allows the cell suspension to perfectly match the shape of the first sub-receptacle 3021. In particular, it allows the cell suspension to fill the space occupied by the four rounded chamfers of the first sub-receptacle 3021, thereby effectively reducing or even avoiding differences in the volume contained in the first sub-receptacle 3021 and improving the precision of cell suspension manipulation.

[0093] Similarly, the four rounded chamfers of the first receiving portion 301 can reduce the dead volume of the first fluid within the first receiving portion 301, thereby improving the liquid storage accuracy of the first receiving portion 301. The four rounded chamfers of the second sub-receiving portion 3022 of the second receiving portion 302 can reduce the dead volume of the biochemical reagent within the second sub-receiving portion 3022, thereby improving the liquid storage accuracy of the second sub-receiving portion 3022.

[0094] Continue to refer to Figure 1C Each of the first receiving portion 301 and the second receiving portion 302 of the microfluidic chip 300, including the first receiving portion 301 and the second receiving portion 302, is provided with a filter structure 312. Since the filter structures 312 of the first receiving portion 301, the first receiving portion 3021, and the second receiving portion 3022 are constructed in exactly the same way, the structure and function of the filter structure 312 will be described in detail below using the filter structure 312 in the first receiving portion 3021 as an example.

[0095] like Figure 1CAs shown, the filter structure 312 includes multiple microstructures spaced apart from each other. The gap d between two adjacent microstructures 312-1 and 312-2 is greater than 1 times the particle size of a single cell and less than 2 times the particle size of a single cell. In some embodiments, the particle size of a single cell derived from a cell suspension is approximately 10 μm, and correspondingly, the gap d between two adjacent microstructures 312-1 and 312-2 is greater than 10 μm and less than 20 μm. The heights of the multiple microstructures of the filter structure 312 can be exactly the same, completely different, or only partially the same. The specific height can be flexibly designed according to product requirements, and the embodiments of this disclosure do not specifically limit this. In some embodiments, the height of each micropillar is approximately 100-200 μm. In the direction parallel to the plane of the first sub-receiving portion 3021, the shape of the cross-section of each micropillar can be any suitable shape, such as rhombus, square, rectangle, circle, ellipse, regular polygon, irregular shape, etc., and the embodiments of this disclosure do not specifically limit this.

[0096] During operation of the microfluidic chip 300, the cell suspension in the first sub-receptacle 3021 flows through the gap between adjacent microstructures of the filter structure 312 and then flows into the first branch of the first sub-channel 3032-1 of the second delivery channel 3032. Since the gap d between two adjacent microstructures is greater than 1 times the particle size of a single cell but less than 2 times the particle size of a single cell, when the cell suspension flows through the gap between adjacent microstructures, on the one hand, it can prevent excessively large impurities in the cell suspension (such as impurities with a particle size greater than 2 times the particle size of a single cell, such as dust, salting-out substances, etc.) from flowing into the subsequent flow channel, thereby avoiding excessively large impurities from clogging the flow channel and affecting the normal flow of the cell suspension; on the other hand, under the force of the adjacent microstructures on the cell suspension and the size selection of the cell suspension by the gap between adjacent microstructures, multiple cells that are stuck together in the cell suspension (such as two, three or more cells that are stuck together) can be separated into multiple separate single cells, which is beneficial for preparing droplets containing single cells and reducing the probability of a single droplet containing two or more cells.

[0097] The structure of the filter structure 312 within the first receiving portion 301 and the second sub-receiving portion 3022 can be referenced above in the description of the filter structure within the first sub-receiving portion 3021, and will not be repeated here for the sake of brevity. During the operation of the microfluidic chip 300, the first fluid within the first receiving portion 301 flows through the gaps between adjacent microstructures of the filter structure 312, and then flows into the first delivery channel 3031 of the delivery channel 303. When the first fluid flows through the gaps between adjacent microstructures of the filter structure 312, it can prevent excessively large impurities (e.g., impurities with a particle size greater than twice the size of a single cell, such as dust, salting-out substances, etc.) in the first fluid from flowing into the first delivery channel 3031, thereby preventing excessively large impurities from clogging the first delivery channel 3031 and affecting the normal flow of the first fluid. During the operation of the microfluidic chip 300, the biochemical reagent in the second sub-receptacle 3022 flows through the gaps between adjacent microstructures of the filter structure 312, and then flows into the second branch of the first sub-channel 3032-1 of the second delivery channel 3032. When the biochemical reagent flows through the gaps between adjacent microstructures of the filter structure 312, it can prevent excessively large impurities (e.g., impurities with a particle size greater than twice the size of a single cell, such as dust, salting-out substances, etc.) from flowing into the second branch of the first sub-channel 3032-1, thereby preventing excessively large impurities from clogging the second branch and affecting the normal flow of the biochemical reagent.

[0098] Figure 2 A schematic diagram of the microfluidic chip 400 is shown, where (a) is a front view of the microfluidic chip 400, (b) is a left view of the microfluidic chip 400, (c) is a rear view of the microfluidic chip 400, and (d) is an axial view of the microfluidic chip 400. The microfluidic chip 400 can be used to sort target droplets, including single target cells, from droplets. The microfluidic chip 400 can be used independently as a separate component to achieve target droplet sorting, or it can be used to replace the sorting channel 305 and collection section 306 of the microfluidic chip 300, thereby enabling the preparation of droplets containing single cells and the sorting of target droplets.

[0099] like Figure 2As shown, the microfluidic chip 400 includes a sorting channel 403, a connecting channel 404, and collecting sections 405 and 406. The sorting channel 403 includes a first sorting channel 4031 and a second sorting channel 4032. The second sorting channel 4032 includes cascaded first-level branches 4032A, 4032B, and 4032C. The connecting channel 404 includes a first connecting channel 4041, a second connecting channel 4042, and a third connecting channel 4043. The collecting section includes a first collecting section 405 and a second collecting section 406. The second collecting section 406 includes a first sub-collecting section 4061, a second sub-collecting section 4062, and a third sub-collecting section 4063. Optionally, the microfluidic chip 400 may further include two third receptacles 401 and one fourth receptacle 402. Each third receptacle 401 is configured to contain a first fluid of the oil phase, and the fourth receptacle 402 is configured to contain a large number of droplets, including target droplets and non-target droplets, wherein each target droplet includes a single target cell. These droplets can be prepared using other devices. As shown, the beginning of the first sorting channel 4031 is connected to the fourth receptacle 402, the end of the first sorting channel 4031 is connected to the first collection section 405, and the first sorting channel 4031 is connected to a first-stage branch 4032A of the second sorting channel 4032 via a first connecting channel 4041. The beginning of the first-level branch 4032A of the second sorting channel 4032 is connected to the third receiving portion 401, and the end of the first-level branch 4032A of the second sorting channel 4032 is connected to the first sub-collecting portion 4061. The first-level branch 4032A and the second-level branch 4032B of the second sorting channel 4032 are connected via the second connecting channel 4042. The beginning of the second-level branch 4032B of the second sorting channel 4032 is connected to the third receiving portion 401, and the end of the second-level branch 4032B of the second sorting channel 4032 is connected to the second sub-collecting portion 4062. The second-level branch 4032B and the third-level branch 4032C of the second sorting channel 4032 are connected via the third connecting channel 4043. The beginning of the third-level branch 4032C of the second sorting channel 4032 is connected to the third connecting channel 4043, and the end of the third-level branch 4032C of the second sorting channel 4032 is connected to the third sub-collection section 4063. The microfluidic chip 400 may also include multiple optical recognition devices and multiple driving electrode devices (not shown in the figure) to enable the microfluidic chip 400 to perform cascade sorting of target cells.

[0100] In a cell suspension, there may be only one type of target cell or multiple different types of target cells. When multiple different types of target cells are present, these different types of target cells need to be screened out separately and collected into different collection sections for subsequent detection.

[0101] The process of target droplet sorting using the microfluidic chip 400 is roughly as follows: a first fluid is added to the third containment 401, and droplets prepared using other devices (such as other microfluidic chips) are added to the fourth containment 402. These droplets include target droplets and non-target droplets, where the target droplets include a single target cell. Assume the droplets include four different types of cells: A, B, C, and D, where A, B, and C types are target cells, and D type cells are non-target cells. Therefore, target droplets include: (a) droplets containing a single type A target cell, (b) droplets containing a single type B target cell, and (c) droplets containing a single type C target cell; non-target droplets include: (d) droplets containing one or more type D non-target cells. The droplets have been stained in the preceding stage.

[0102] The droplets in the fourth receiving section 402 flow into the first sorting channel 4031. At the connection point between the first sorting channel 4031 and the first connecting channel 4041, the first optical recognition device detects the optical signal (e.g., color) of the droplets in real time. When the first optical recognition device detects that the droplet is in condition (d) above, it does not notify the circuit system, and the circuit system therefore does not apply voltage to the first driving electrode device associated with the first optical recognition device. Therefore, the non-target droplets continue to move along the first sorting channel 4031 until they flow into the first collection section 405. When the first optical recognition device detects that the droplet is in any of the above conditions (a)-(c), it immediately notifies the circuit system to apply an appropriate voltage to the first driving electrode device. The target droplet is polarized, and under the action of the electric field, the target droplet deflects upward and flows into the first connecting channel 4041, and then flows into the first-stage branch 4032A of the second sorting channel 4032 via the first connecting channel 4041. At the connection point between the first-stage branch 4032A and the second connecting channel 4042, the second optical recognition device detects the optical signal of the target droplet in real time. When the second optical recognition device detects that the target droplet is in condition (a) as described above, it does not notify the circuit system, and therefore the circuit system does not apply voltage to the second driving electrode device associated with the second optical recognition device. As a result, the target droplet (a) continues to move along the first-stage branch 4032A until it flows into the first sub-collection section 4061, thereby allowing the target droplet containing a single type A target cell to be screened from the droplets. When the second optical recognition device detects that the target droplet is in condition (b) or (c) as described above, it immediately notifies the circuit system to apply an appropriate voltage to the second driving electrode device. The target droplet (b) or (c) is polarized, and under the action of the electric field, the target droplet (b) or (c) is deflected upward and flows into the second connecting channel 4042, and then flows into the second-stage branch 4032B via the second connecting channel 4042. At the connection point between the second-level branch 4032B and the third connecting channel 4043, the third optical recognition device performs real-time detection of the optical signal of the target droplet (b) or (c). When the third optical recognition device detects that the target droplet is in condition (b) as described above, it does not notify the circuit system, and the circuit system therefore does not apply voltage to the third driving electrode device associated with the third optical recognition device. As a result, the target droplet (b) continues to move along the second-level branch 4032B until it flows into the second sub-collection section 4062, thereby allowing the target droplet containing a single type B target cell to be screened from the droplet.When the third optical recognition device detects that the target droplet is in the above condition (c), it immediately notifies the circuit system to apply an appropriate voltage to the third driving electrode device. The target droplet (c) is polarized. Under the action of the electric field, the target droplet (c) deflects upward and flows into the third connecting channel 4043. Then, it flows into the third branch 4032C through the third connecting channel 4043 and finally flows into the third sub-collection section 4063, thereby screening out the target droplet containing a single C-type target cell from the droplet.

[0103] Using this microfluidic chip 400, three different types of target cells can be screened in a single sorting process, which greatly improves the speed and efficiency of cell sorting. Moreover, compared to using three different microfluidic chips to screen three different types of target cells separately, the embodiments of this disclosure only use one microfluidic chip 400 to achieve the sorting of three different types of target cells, which greatly saves the number of microfluidic chips required, thereby saving production costs.

[0104] When the sorting channel 305 and the collection section 306 of the microfluidic chip 300 are replaced by the microfluidic chip 400, the fourth receiving section 402 can be omitted. Alternatively, the beginning of the first sorting channel 4031 is connected to the end of the third sub-channel 3032-3 of the microfluidic chip 300, while the other configurations of the microfluidic chip 400 remain unchanged. In this way, the droplet generated at the confluence point 304 flows into the first sorting channel 4031 along the third sub-channel 3032-3, and then the droplet undergoes the cascade sorting as described above. With this design, using a single microfluidic chip, not only can droplets containing single cells be prepared, but also such droplets can be cascaded and sorted to separate various types of target cells.

[0105] In actual operation, the first fluid of the oil phase in the third containment 401 can be pre-filled with the microfluidic chip 400, which can promote smoother flow of droplets in the sorting channel 403.

[0106] like Figure 2 As shown, one end of the first connecting channel 4041 is located between the beginning and end of the first sorting channel 4031, and the other end of the first connecting channel 4041 is located between the beginning and end of the first-level branch 4032A; one end of the second connecting channel 4042 is located between the beginning and end of the first-level branch 4032A, and the other end of the second connecting channel 4042 is located between the beginning and end of the second-level branch 4032B, and the second connecting channel 4042 is located relative to the first connecting channel 4041 in the second direction (i.e. Figure 2In the second direction, the first connecting channel 4042 is closer to the collection section (i.e., in the figure, the second connecting channel 4042 is offset to the right relative to the first connecting channel 4041 by a certain distance); one end of the third connecting channel 4043 is located between the beginning and end of the second-level branch 4032B, and the other end of the third connecting channel 4043 is connected to the beginning of the third-level branch 4032C, and the third connecting channel 4043 is closer to the collection section in the second direction than the second connecting channel 4042 (i.e., in the figure, the third connecting channel 4043 is offset to the right relative to the second connecting channel 4042 by a certain distance). In other words, in the second direction, the first connecting channel 4041 is located to the left of the second connecting channel 4042, and the second connecting channel 4042 is located to the left of the third connecting channel 4043. With this arrangement, droplets can smoothly flow from the first sorting channel 4031 into the first-level branch 4032A, the second-level branch 4032B, and the third-level branch 4032C of the second sorting channel 4032, thereby achieving the cascaded sorting described above. Furthermore, the sorting channel 403 and the connecting channel 404 are configured such that droplets flow from the first sorting channel 4031 through the connecting channel 404 into the first-level branch 4032A, the second-level branch 4032B, and the third-level branch 4032C of the second sorting channel 4032, and the flow direction of the droplets is irreversible. This arrangement prevents droplets flowing into the next level branch from flowing back into the previous level branch, thereby avoiding cross-contamination of different types of target cells.

[0107] It should be noted that, although Figure 2 The second sorting channel 4032 of the microfluidic chip 400 shown includes three branches 4032A, 4032B, and 4032C. However, this is only an example, and the number of branches in the second sorting channel 4032 depends on the number of target cell types to be sorted. The embodiments of this disclosure do not specifically limit this. For example, when it is necessary to sort N (N≥2) different types of target cells from a droplet, the microfluidic chip 400 may include N connecting channels, and the second sorting channel 4032 may include N cascaded branches. A connecting channel is provided between any two adjacent branches of these N cascaded branches, and any two adjacent branches are connected via this connecting channel. Correspondingly, the second collection section 406 includes N sub-collection sections. The N cascaded branches of the second sorting channel 4032 correspond one-to-one with the N sub-collection sections, and one of the N cascaded branches is connected to the corresponding one of the N sub-collection sections.

[0108] Figure 3 A variant 400' of the microfluidic chip 400 is shown, wherein (a) is a front view of the microfluidic chip 400', (b) is a left view of the microfluidic chip 400', (c) is a rear view of the microfluidic chip 400', and (d) is an axial view of the microfluidic chip 400'. Figure 3 The microfluidic chip 400' shown is... Figure 2 Compared to the microfluidic chip 400 shown, the two have similar structures except for the sorting channel 403 and the collection sections 405' and 406. The same reference numerals refer to the same components; therefore, for the sake of brevity, the functions and roles of these identical components will not be described again, but can be found in the description of the microfluidic chip 400. Only the different parts will be described below.

[0109] The microfluidic chip 400' can be used to sort target droplets, including individual target cells, from droplets. The microfluidic chip 400' can be used independently as a component to sort target droplets, or it can be used to replace the sorting channel 305 and the collection section 306 of the microfluidic chip 300, thereby enabling the preparation of droplets containing individual cells and the sorting of target droplets.

[0110] like Figure 3 As shown, the microfluidic chip 400' includes a sorting channel 403, a connecting channel 404, and collection sections 405' and 406. The sorting channel 403 includes a first sorting channel 4031 and a second sorting channel 4032. The first sorting channel 4031 includes cascaded first-level branches 4031A, second-level branches 4031B, and third-level branches 4031C. The connecting channel 404 includes a first connecting channel 4041, a second connecting channel 4042, and a third connecting channel 4043. The collection sections include a first collection section 405' and a second collection section 406. Optionally, the microfluidic chip 400' may also include two third receiving sections 401 and a fourth receiving section 402. Each third receiving section 401 is configured to receive a first fluid of the oil phase, and the fourth receiving section 402 is configured to receive a large number of droplets, including target droplets and non-target droplets, wherein each target droplet includes a single target cell. Figure 3As shown, the beginning of the first-level branch 4031A of the first sorting channel 4031 is connected to the fourth receiving portion 402, the end of the first-level branch 4031A of the first sorting channel 4031 is connected to the first collecting portion 405', and the first-level branch 4031A and the second-level branch 4031B of the first sorting channel 4031 are connected via the first connecting channel 4041. The beginning of the second-level branch 4031B of the first sorting channel 4031 is connected to the third receiving portion 401, the end of the second-level branch 4031B of the first sorting channel 4031 is connected to the first collecting portion 405', and the second-level branch 4031B and the third-level branch 4031C of the first sorting channel 4031 are connected via the second connecting channel 4042. The beginning of the third-level branch 4031C of the first sorting channel 4031 is connected to the third receiving portion 401, and the end of the third-level branch 4031C of the first sorting channel 4031 is connected to the first collecting portion 405'. The third-level branch 4031C of the first sorting channel 4031 is also connected to the second sorting channel 4032 via the third connecting channel 4043. The beginning of the second sorting channel 4032 is connected to the third connecting channel 4043, and the end of the second sorting channel 4032 is connected to the second collecting portion 406. The microfluidic chip 400' may further include multiple optical recognition devices and multiple driving electrode devices (not shown in the figure) to enable the microfluidic chip 400' to achieve cascade sorting of target cells.

[0111] When a target cell type is present in a cell suspension, a situation may arise where this target cell type is very similar to non-target cells in the cell suspension, making them difficult to distinguish. Therefore, it is difficult to screen out the desired target cells from the cell suspension using only a single sorting process, or the success rate of screening out the desired target cells from the cell suspension using only a single sorting process is low. Therefore, unlike microfluidic chip 400, this microfluidic chip 400' is not used to simultaneously screen out multiple different types of target cells, but rather to improve the purity of the sorted target cells.

[0112] The process of target droplet sorting using the microfluidic chip 400' is roughly as follows: a first fluid is added to the third receiving portion 401, and droplets prepared using other devices (such as other microfluidic chips) are added to the fourth receiving portion 402. These droplets include target droplets and non-target droplets, where the target droplets include a single target cell. Assuming the droplets include two different types of cells, E and F, where type E cells are target cells and type F cells are non-target cells, and type E target cells and type F non-target cells are difficult to distinguish, the target droplets include: (e) droplets containing a single type E target cell; the non-target droplets include: (f) droplets containing one or more type F non-target cells. The droplets have been pre-stained. The droplets in the fourth receiving portion 402 flow into the first branch 4031A of the first sorting channel 4031. At the connection point between the first branch 4031A and the first connecting channel 4041, a first optical recognition device performs real-time detection of the droplet's optical signal (e.g., color). When the first optical recognition device detects that the droplet is in condition (f) as described above, it will not notify the circuit system, and the circuit system will therefore not apply voltage to the first driving electrode device associated with the first optical recognition device. Therefore, the non-target droplet continues to move along the first branch 4031A until it flows into the first collection section 405'. When the first optical recognition device determines that the droplet is in condition (e) as described above, it immediately notifies the circuit system to apply an appropriate voltage to the first driving electrode device. The droplet (which still actually includes a portion of the non-target droplet) is polarized, and under the action of the electric field, the droplet deflects upward and flows into the first connecting channel 4041, and then flows into the second branch 4031B via the first connecting channel 4041. At the connection point between the second branch 4031B and the second connecting channel 4042, the second optical recognition device performs real-time detection of the droplet's optical signal. When the second optical recognition device detects that condition (f) still exists in the droplet, it will not notify the circuit system, and the circuit system will therefore not apply voltage to the second driving electrode device associated with the second optical recognition device. Therefore, the further filtered non-target droplets (f) continue to move along the second-level branch 4031B and eventually flow into the first collection section 405'. When the second optical recognition device determines that the droplet is in the above-described condition (e), it immediately instructs the circuit system to apply an appropriate voltage to the second driving electrode device. The droplet is polarized, and under the action of the electric field, the droplet deflects upward and flows into the second connecting channel 4042, and then flows into the third-level branch 4031C via the second connecting channel 4042. At the connection position between the third-level branch 4031C and the third connecting channel 4043, the third optical recognition device performs real-time detection of the optical signal of the droplet (which still actually includes a small number of non-target droplets).When the third optical recognition device detects that the droplet still exists under the aforementioned condition (f), it does not notify the circuit system, and therefore the circuit system does not apply voltage to the third driving electrode device associated with the third optical recognition device. Thus, the non-target droplet continues to move along the third branch 4031C and then flows into the first collection section 405'. When the third optical recognition device detects that the droplet is under the aforementioned condition (e), it immediately notifies the circuit system to apply an appropriate voltage to the third driving electrode device. The target droplet (e) is polarized, and under the action of the electric field, the target droplet (e) deflects upward and flows into the third connecting channel 4043, then flows through the third connecting channel 4043 into the second sorting channel 4032, and finally into the second collection section 406, thereby filtering out the target droplet containing a single type E target cell from the droplet.

[0113] By using this microfluidic chip 400', multiple cascaded sorting of droplets can distinguish between target droplets and non-target droplets that are difficult to differentiate, greatly improving the purity of the final collected target droplets and reducing or even eliminating the possibility that the collected target droplets contain non-target droplets.

[0114] It should be noted that, although Figure 3 The first sorting channel 4031 of the microfluidic chip 400' shown includes three branches 4031A, 4031B, and 4031C. However, this is only an example. The specific number of branches of the first sorting channel 4031 can be determined according to the difficulty of distinguishing between target cells and non-target cells. The embodiments of this disclosure do not specifically limit this.

[0115] When the sorting channel 305 and collection section 306 of the microfluidic chip 300 are replaced by the microfluidic chip 400', the fourth receiving section 402 can be omitted. Instead, the beginning of the first-level branch 4031A of the first sorting channel 4031 is connected to the end of the third sub-channel 3032-3 of the microfluidic chip 300, while the other configurations of the microfluidic chip 400' remain unchanged. In this way, the droplet generated at the confluence point 304 flows along the third sub-channel 3032-3 into the first-level branch 4031A of the first sorting channel 4031, and then the droplet undergoes the cascade sorting process described above. With this design, using a single microfluidic chip, not only can droplets containing single cells be prepared, but such droplets can also be cascaded and sorted, thereby distinguishing between target droplets and non-target droplets that are difficult to differentiate, greatly improving the purity of the finally collected target droplets.

[0116] Figure 4A schematic diagram of the microfluidic chip 500 is shown, where (a) is a front view of the microfluidic chip 500, (b) is a left view of the microfluidic chip 500, (c) is a rear view of the microfluidic chip 500, and (d) is an axial view of the microfluidic chip 500. The microfluidic chip 500 can be used to separate two droplets with different particle sizes from a liquid droplet. The microfluidic chip 500 can be used independently as a separate component, or it can replace the sorting channel 305 and the collection section 306 of the microfluidic chip 300, thereby enabling the preparation of droplets containing single cells and the sorting of target droplets.

[0117] like Figure 4 As shown, the microfluidic chip 500 includes a sorting channel 502 and a collecting section 506. The sorting channel 502 includes a main channel 503, a first sorting channel 504, and a second sorting channel 505. The collecting section 506 includes a first collecting section 507 and a second collecting section 508. The main channel 503 is spiral-shaped in the plane of the microfluidic chip 500. The end of the main channel 503 communicates with the first sorting channel 504 and the second sorting channel 505. The end of the first sorting channel 504 communicates with the first collecting section 507, and the end of the second sorting channel 505 communicates with the second collecting section 508. Optionally, the microfluidic chip 500 may further include a third receiving section 501, which is configured to receive droplets, including first-type droplets and second-type droplets with different particle sizes.

[0118] The cell suspension includes cells with smaller particle sizes and cells with larger particle sizes. When such a cell suspension is mixed with a first fluid and forms droplets containing individual cells through the aforementioned process, the resulting droplets also have different particle sizes. Here, droplets containing cells with smaller particle sizes are referred to as first-type droplets, which have smaller particle sizes; droplets containing cells with larger particle sizes are referred to as second-type droplets, which have larger particle sizes. When the droplets are sorted using the microfluidic chip 500, the droplets in the third receiving portion 501 flow into the spiral-shaped main flow channel 503. Due to the difference in droplet particle size, their inertial forces are different. At the bifurcation point at the end of the main flow channel 503, the first-type droplets with smaller particle sizes experience less inertial force and therefore enter the first sorting flow channel 504 along the extension direction of the main flow channel 503, and then flow into the first collection portion 507. The larger droplets of the second type are subject to greater inertial force. Under the influence of inertial force, they are thrown out of the main flow channel 503 and enter the second sorting flow channel 505, and finally flow into the second collection section 508.

[0119] Figure 4The shape of the main flow channel 503 is shown only as an example, but the shape of the main flow channel 503 is not limited to this, as long as the shape of the main flow channel 503 allows droplets of different sizes to enter different sorting channels under the action of different inertial forces.

[0120] This microfluidic chip 500 eliminates the need for optical recognition devices and driving electrodes, relying solely on the shape of the main flow channel 503 to separate droplets of different sizes. Because it eliminates the need for optical recognition devices and driving electrodes, it not only reduces the size of the microfluidic chip 500 but also saves on production costs.

[0121] When the sorting channel 305 and the collection section 306 of the microfluidic chip 300 are replaced by the microfluidic chip 500, the third receiving section 501 can be omitted. Instead, the beginning of the main channel 503 is connected to the end of the third sub-channel 3032-3 of the microfluidic chip 300, while the other configurations of the microfluidic chip 500 remain unchanged. In this way, the droplet generated at the confluence point 304 flows into the main channel 503 along the third sub-channel 3032-3, and then the sorting operation described above is performed on the droplet. With this design, using a single microfluidic chip, not only can droplets containing single cells be prepared, but droplets of different sizes can also be separated.

[0122] The inventors of this application have discovered that, in conventional techniques, the first and second fluids (including cell suspension and biochemical reagents) described in the above embodiments need to be stored separately in external devices independent of the microfluidic chip. During the operation of the microfluidic chip, each time, it is necessary to manually connect the external device to the inlet of the microfluidic chip using a flexible conduit to inject the first and second fluids into the microfluidic chip in real time. The microfluidic chip then processes the fluids to prepare droplets and / or sort target droplets from the droplets. Therefore, to achieve droplet preparation and / or target droplet sorting, at least the external device for storing the fluids, the flexible conduit, and the microfluidic chip are required. This makes the system bulky and inconvenient to carry. Furthermore, when changing the microfluidic chip to prepare different reagents, the external device needs to be cleaned to accommodate the new reagents required for the new microfluidic chip. However, it is usually impossible to guarantee that the external device can be thoroughly cleaned, so residual reagents can easily remain in the external device, causing contamination of the new reagents.

[0123] Therefore, embodiments of this disclosure provide a housing device adapted to microfluidic chips, each microfluidic chip having a corresponding housing device, which can be coupled to the microfluidic chip using an appropriate bonding method. The housing device can store reagents and release reagents into the inlet of the microfluidic chip, and can also receive and store reagents flowing into the housing device from the outlet of the microfluidic chip. This housing device can provide a sterile environment because the cell suspension can be completely confined within the sealed housing device before and after cell sorting.

[0124] Figure 5A A schematic diagram of the structure of a housing device 1000 according to an embodiment of the present disclosure is shown, wherein (a) is a front view of the housing device 1000, (b) is a right view of the housing device 1000, (c) is a top view of the housing device 1000, and (d) is an axial view of the housing device 1000. Figure 5B A schematic diagram of the microfluidic chip 100 is shown, which is described in priority application (NO. 202180000922.0). A housing device 1000 is adapted to the microfluidic chip 100, and the combination of the two can be used to prepare droplets containing single cells. The specific droplet preparation process can be found in the priority application.

[0125] refer to Figure 5A and 5B The housing device 1000 is configured to be used in conjunction with a microfluidic chip 100, which includes inlet ports 1, 2, and 3 and outlet port 4. The housing device 1000 includes: a receiving cavity configured to receive the microfluidic chip 100; an inlet unit 1001 connected to the inlets 1, 2, and 3 of the microfluidic chip 100, configured to store a first reagent and release the first reagent into the inlets 1, 2, and 3 of the microfluidic chip 100; and an outlet unit 1002 connected to the outlet port 4 of the microfluidic chip 100, configured to receive and store a second reagent processed by the microfluidic chip 100 and flowing into the outlet unit 1002 from the outlet port 4 of the microfluidic chip 100, the second reagent comprising target droplets, each target droplet comprising a single target cell. The sample injection unit 1001 includes sample injection holes 1003A / 1004A / 1005A and first storage cavities 1003B / 1004B / 1005B. Each sample injection hole is a through hole and communicates with the corresponding first storage cavity. Each sample injection hole is recessed from the surface of the housing device 1000 into the interior of the housing device 1000, and the first storage cavity corresponding to the sample injection hole is located on the side of the sample injection hole away from the surface of the housing device 1000.

[0126] By providing a housing device 1000, each microfluidic chip 100 can be configured with a separate housing device 1000. This housing device 1000 can store the injection reagent (i.e., the first reagent) required by the microfluidic chip 100 and the output reagent (i.e., the second reagent) processed by the microfluidic chip 100. Therefore, there is no need to provide an external storage device, which can greatly reduce the size of the device and make it easy to carry. In addition, since each microfluidic chip 100 is configured with a separate housing device 1000, which stores the first reagent required by the microfluidic chip 100 and the output second reagent, there is no risk of cross-contamination of reagents in external storage devices due to replacement of microfluidic chips, as is the case in conventional technologies. Furthermore, the sample introduction unit 1001 includes a sample introduction port and a first storage cavity. This design can better guide the first reagent from the sample introduction port into the first storage cavity, and then through the first storage cavity into the sample introduction port of the microfluidic chip 100.

[0127] Continue to refer to Figure 5A and 5B The sample injection unit 1001 of the box device 1000 includes a first sample injection unit 1003, a second sample injection unit 1004, and a third sample injection unit 1005. The sample injection port of the microfluidic chip 100 includes a first sample injection port 1, a second sample injection port 2, and a third sample injection port 3. The first reagent includes a first sub-reagent (i.e., a first fluid), a second sub-reagent (i.e., a cell suspension), and a third sub-reagent (i.e., a biochemical reagent). The first sample introduction unit 1003 of the cartridge device 1000 is connected to the first sample inlet 1 of the microfluidic chip 100. The first sample introduction unit 1003 is configured to store a first sub-reagent and release the first sub-reagent into the first sample inlet 1 of the microfluidic chip 100. The second sample introduction unit 1004 of the cartridge device 1000 is connected to the second sample inlet 2 of the microfluidic chip 100. The second sample introduction unit 1004 is configured to store a second sub-reagent and release the second sub-reagent into the second sample inlet 2 of the microfluidic chip 100. The third sample introduction unit 1005 of the cartridge device 1000 is connected to the third sample inlet 3 of the microfluidic chip 100. The third sample introduction unit 1005 is configured to store a third sub-reagent and release the third sub-reagent into the third sample inlet 3 of the microfluidic chip 100. The sample dispensing unit 1002 of the cartridge device 1000 includes a sample dispensing unit 1006, which receives and stores a second reagent, including target droplets and non-target droplets.

[0128] As shown in the figure, the first injection unit 1003 includes an injection port 1003A and a first storage cavity 1003B, the second injection unit 1004 includes an injection port 1004A and a first storage cavity 1004B, and the third injection unit 1005 includes an injection port 1005A and a first storage cavity 1005B. The first injection unit 1003, the second injection unit 1004, and the third injection unit 1005 have the same structure. The following description of the structure of each injection unit uses the first injection unit 1003 as an example. Since the first injection unit 1003, the second injection unit 1004, and the third injection unit 1005 have the same structure, the following description of the structure of the first injection unit 1003 also applies to the second injection unit 1004 and the third injection unit 1005.

[0129] The first storage cavity 1003B of the first sample injection unit 1003 is located inside the housing device 1000, and the orthographic projection of the sample injection port 1003A on the housing device 1000 falls within the orthographic projection of the first storage cavity 1003B on the housing device 1000. For example, as Figure 5A As shown, the width of the injection port 1003A in the lateral direction is smaller than the width of the first storage cavity 1003B in the lateral direction. With this arrangement, the flow rate of the first sub-reagent in the injection port 1003A can be increased, which promotes the flow of the first sub-reagent from the injection port 1003A into the first storage cavity 1003B, and finally into the first injection port 1 of the microfluidic chip 100.

[0130] In some embodiments, the first sample injection unit 1003 may further include a second storage cavity 1003C (similarly, the second sample injection unit 1004 may further include a second storage cavity 1004C, and the third sample injection unit 1005 may further include a second storage cavity 1005C). The second storage cavity 1003C is located on the side of the first storage cavity 1003B away from the sample injection port 1003A and communicates with the first storage cavity 1003B. The second storage cavity 1003C includes a first opening communicating with the first storage cavity 1003B and a second opening opposite to the first opening. The orthographic projection of the second opening of the second storage cavity 1003C onto the housing device 1000 falls within the orthographic projection of the first opening onto the housing device 1000. In one example, such as Figure 5A As shown, the second storage cavity 1003C has a bowl-shaped form, that is, the second storage cavity 1003C is wider at the top and narrower at the bottom. With this arrangement, the second storage cavity 1003C can effectively collect the first sub-reagent flowing into it from the first storage cavity 1003B and guide the first sub-reagent to the first injection port 1 of the microfluidic chip 100. In some embodiments, the orthographic projection of the second opening of the second storage cavity 1003C on the housing device 1000 falls within the orthographic projection of the injection port 1003A on the housing device 1000.

[0131] Continue to refer to Figure 5A The sample dispensing unit 1006 of the housing device 1000 includes a sample dispensing hole 1006A and a third storage cavity 1006B. The sample dispensing hole 1006A is a through hole and communicates with the third storage cavity 1006B. The sample dispensing hole 1006A is recessed from the surface of the housing device 1000 into the interior of the housing device 1000, and the third storage cavity 1006B is located on the side of the sample dispensing hole 1006A away from the surface of the housing device 1000. In some embodiments, the third storage cavity 1006B is located inside the housing device 1000, and the orthographic projection of the sample dispensing hole 1006A onto the housing device 1000 falls within the orthographic projection of the third storage cavity 1006B onto the housing device 1000. For example, as... Figure 5A As shown, the width of the sample outlet 1006A in the lateral direction is smaller than the width of the third storage cavity 1006B in the lateral direction. With this arrangement, the third storage cavity 1006B mainly serves to store the second reagent, while the sample outlet 1006A can better facilitate the transfer of the second reagent in the third storage cavity 1006B to external devices (if necessary).

[0132] In some embodiments, the sample dispensing unit 1006 may further include a fourth storage cavity 1006C, which is located on the side of the third storage cavity 1006B away from the sample dispensing port 1006A and communicates with the third storage cavity 1006B. The fourth storage cavity 1006C can be used to connect the sample dispensing port 4 of the microfluidic chip 100 and the sample dispensing unit 1006 of the housing device 1000, and guide the second reagent flowing out from the sample dispensing port 4 of the microfluidic chip 100 to the third storage cavity 1006B of the housing device 1000. In some embodiments, the orthographic projection of the fourth storage cavity 1006C on the housing device 1000 and the orthographic projection of the sample dispensing port 1006A on the housing device 1000 overlap by at most a portion.

[0133] The general process of preparing droplets containing single cells using the housing device 1000 and the microfluidic chip 100 can be described as follows:

[0134] (1) A first fluid, cell suspension and biochemical reagent are pre-added to the first injection unit 1003, the second injection unit 1004 and the third injection unit 1005 respectively. The first fluid is an oil phase and may contain surfactants.

[0135] (2) The injection ports of the first injection unit 1003, the second injection unit 1004 and the third injection unit 1005 of the box device 1000 are connected to the flow pump through a flexible pipe, and the flow rate of fluid injected into the injection unit is controlled by adjusting the pressure of the flow pump.

[0136] (3) The first fluid in the first injection unit 1003 flows into the first injection port 1 of the microfluidic chip 100 through the injection port 1003A, the first storage chamber 1003B, and the second storage chamber 1003C; the cell suspension in the second injection unit 1004 flows into the second injection port 2 of the microfluidic chip 100 through the injection port 1004A, the first storage chamber 1004B, and the second storage chamber 1004C; the biochemical reagent in the third injection unit 1005 flows into the third injection port 3 of the microfluidic chip 100 through the injection port 1005A, the first storage chamber 1005B, and the second storage chamber 1005C. Note that the microfluidic chip 100 can be filled with the first fluid of the oil phase first, and then the cell suspension and biochemical reagent can be injected.

[0137] (4) The first fluid, cell suspension, and biochemical reagents converge at the confluence point 105 of the microfluidic chip 100 to form a droplet (i.e., the second reagent). This droplet includes target droplets and non-target droplets, wherein the target droplet includes a single target cell. The droplet flows into the first collection section 104 via the delivery channel 103 of the microfluidic chip 100, and then flows into the sample dispensing unit 1006 of the housing device via the sample outlet 4 at the first collection section 104. The sample dispensing unit 1006 can store the droplet or transfer it to other devices as needed.

[0138] Figure 6A A schematic diagram of the structure of a housing device 2000 according to another embodiment of the present disclosure is shown, wherein (a) is a front view of the housing device 2000, (b) is a right view of the housing device 2000, (c) is a top view of the housing device 2000, and (d) is an axial view of the housing device 2000. Figure 6B A schematic diagram of the microfluidic chip 200, described in priority application (NO. 202180000922.0), is shown. A housing device 2000 is adapted to the microfluidic chip 200, and the combination of the two can be used to sort droplets to obtain target droplets. The specific droplet sorting process can be found in the priority application.

[0139] The cartridge device 2000 includes a sample inlet unit 2001 and a sample outlet unit 2002. The sample inlet unit 2001 is connected to the sample inlet of the microfluidic chip 200 and is configured to store a first reagent and release the first reagent into the sample inlet of the microfluidic chip 200. The first reagent is a large number of droplets, at least a portion of which includes a single cell. The sample outlet unit 2002 is connected to the sample outlet of the microfluidic chip 200 and is configured to receive and store a second reagent processed by the microfluidic chip 200 and flowing into the sample outlet unit 2002 from the sample outlet of the microfluidic chip 200. The second reagent includes target droplets and non-target droplets, wherein the target droplets include a single target cell. The sample introduction unit 2001 includes a first sample introduction unit 2003 and a second sample introduction unit 2004. The sample dispensing unit 2002 includes a first sample dispensing unit 2005, a second sample dispensing unit 2006, and a third sample dispensing unit 2007 located between the first sample dispensing unit 2005 and the second sample dispensing unit 2006. The microfluidic chip 200 has a sample inlet including a first sample inlet 5 and a second sample inlet 6. The first sample introduction unit 2003 is connected to the first sample inlet 5 of the microfluidic chip 200 and is configured to store a first sub-reagent (i.e., a first fluid) and release the first sub-reagent into the first sample inlet 5 of the microfluidic chip 200. The second sample introduction unit 2004 is connected to the second sample inlet 6 of the microfluidic chip 200 and is configured to store a second sub-reagent (i.e., a droplet containing a single cell) and release the second sub-reagent into the second sample inlet 6 of the microfluidic chip 200. The third sample dispensing unit 2007 of the sample dispensing unit 2002 is configured to receive and store non-target droplets, while the first sample dispensing unit 2005 and the second sample dispensing unit 2006 of the sample dispensing unit 2002 are configured to receive and store target droplets.

[0140] The first sample inlet unit 2003 of the cartridge device 2000 includes a sample inlet port 2003A, a first storage chamber 2003B, and a second storage chamber 2003C; the second sample inlet unit 2004 includes a sample inlet port 2004A, a first storage chamber 2004B, and a second storage chamber 2004C. The structures of the first sample inlet unit 2003 and the second sample inlet unit 2004 of the cartridge device 2000 are completely identical to those of the first sample inlet unit 1003 of the cartridge device 1000. Therefore, the first sample inlet unit 2003 and the second sample inlet unit 2004 of the cartridge device 2000 have the same technical effects as the first sample inlet unit 1003 of the cartridge device 1000. For the sake of simplicity, their structure and technical effects will not be repeated here. The first sample dispensing unit 2005 of the box device 2000 includes a sample dispensing hole 2005A, a third storage cavity 2005B, and a fourth storage cavity 2005C. The second sample dispensing unit 2006 of the box device 2000 includes a sample dispensing hole 2006A, a third storage cavity 2006B, and a fourth storage cavity 2006C. The third sample dispensing unit 2007 of the box device 2000 includes a sample dispensing hole 2007A, a third storage cavity 2007B, and a fourth storage cavity 2007C. The first sample dispensing unit 2005, the second sample dispensing unit 2006, and the third sample dispensing unit 2007 have identical structures. Except for the relative positions of the fourth storage cavity and the sample outlet, the structures of the first sample outlet unit 2005, the second sample outlet unit 2006, and the third sample outlet unit 2007 of the box device 2000 are basically the same as the structure of the sample outlet unit 1006 of the box device 1000. Therefore, the structure and technical effects of each sample outlet unit of the box device 2000 can be referenced from the structure and technical effects of the sample outlet unit 1006 of the box device 1000. In the box device 2000, taking the first sample outlet unit 2005 as an example, the orthographic projection of the fourth storage cavity 2005C on the box device 2000 falls within the orthographic projection of the sample outlet 2005A on the box device 2000.

[0141] The housing device 2000 also includes a first mounting area 2008 and a second mounting area 2009. The first mounting area 2008 is configured to mount an optical recognition device, and the second mounting area 2009 is configured to mount a driving electrode device. The optical recognition device and the driving electrode device are used in conjunction with the microfluidic chip 200 to achieve the sorting of target droplets.

[0142] The general process of sorting target droplets using the housing device 2000 and the microfluidic chip 200 can be described as follows:

[0143] (1) A first fluid and a droplet containing a single cell are pre-added to the first injection unit 2003 and the second injection unit 2004, respectively. The droplet can be prepared by the above-mentioned housing device 1000 and microfluidic chip 100. The first fluid is an oil phase, which may be mixed with a surfactant.

[0144] (2) The inlet port 2003A of the first inlet unit 2003 and the inlet port 2004A of the second inlet unit 2004 of the box device 2000 are connected to the corresponding flow pumps through flexible pipes, and the flow rate of fluid injected into the inlet unit is controlled by adjusting the pressure of the flow pump.

[0145] (3) The first fluid in the first injection unit 2003 flows into the first injection port 5 of the microfluidic chip 200 through the injection port 2003A, the first storage chamber 2003B and the second storage chamber 2003C; the droplets in the second injection unit 2004 flow into the second injection port 6 of the microfluidic chip 200 through the injection port 2004A, the first storage chamber 2004B and the second storage chamber 2004C. Note that the microfluidic chip 200 can be filled with the first fluid of the oil phase first, and then the droplets can be injected.

[0146] (4) The droplets are sorted at the sorting channel 203 of the microfluidic chip 200 and enter the corresponding sub-collection section. Target droplets (including single target cells) are collected in the first sub-collection section 2041 and the second sub-collection section 2042, while non-target droplets are collected in the third sub-collection section 2043. Target droplets in the first sub-collection section 2041 flow into the first sample outlet 2005 of the housing device 2000 via the sample outlet 7A. Target droplets in the second sub-collection section 2042 flow into the second sample outlet 2006 of the housing device 2000 via the sample outlet 7B. Non-target droplets in the third sub-collection section 2043 flow into the third sample outlet 2007 of the housing device 2000 via the sample outlet 7C. The first sample outlet 2005, the second sample outlet 2006, and the third sample outlet 2007 can store the corresponding droplets or transfer them to other devices as needed.

[0147] The housing device 2000 is adapted to the microfluidic chip 200 to jointly achieve the sorting of target droplets. Since the droplets are completely confined within the sealed housing device 2000 and microfluidic chip 200 before and after sorting, this housing device 2000 provides a sterile operating environment. Furthermore, the presence of the housing device 2000 makes the system composed of the housing device 2000 and microfluidic chip 200 simpler, more convenient, and easier to carry.

[0148] Figure 7 A schematic diagram of a housing device 3000 according to another embodiment of the present disclosure is shown, wherein (a) is a front view of the housing device 3000, (b) is a right view of the housing device 3000, (c) is a top view of the housing device 3000, and (d) is an axial view of the housing device 3000. The housing device 3000 is adapted to this application. Figure 1AThe microfluidic chip 300 shown, when combined with the microfluidic chip, can be used to prepare droplets including single cells and to sort these droplets to obtain target droplets. The droplet preparation and sorting process can be found in the description of the microfluidic chip 300.

[0149] The cartridge device 3000 includes a sample inlet unit 3001 and a sample outlet unit 3002. The sample inlet unit 3001 is connected to the sample inlet of the microfluidic chip 300 and configured to store a first reagent and release the first reagent into the sample inlet of the microfluidic chip 300. The sample outlet unit 3002 is connected to the sample outlet of the microfluidic chip 300 and configured to receive and store a second reagent processed by the microfluidic chip 300 and flowing into the sample outlet unit 3002 from the sample outlet of the microfluidic chip 300. The second reagent includes target droplets and non-target droplets, wherein the target droplets include a single target cell. The sample inlet unit 3001 includes a first sample inlet unit 3003, a second sample inlet unit 3004, and a third sample inlet unit 3005. The sample outlet unit 3002 includes a first sample outlet unit 3006 and a second sample outlet unit 3007. The microfluidic chip 300 has a sample inlet including a first sample inlet located at a first receiving portion 301, a second sample inlet located at a first sub-receiving portion 3021, and a third sample inlet located at a second sub-receiving portion 3022. A first sample inlet unit 3003 is connected to the first sample inlet of the microfluidic chip 300 and is configured to store a first sub-reagent (i.e., a first fluid) and release the first sub-reagent into the first sample inlet of the microfluidic chip 300. A second sample inlet unit 3004 is connected to the second sample inlet of the microfluidic chip 300 and is configured to store a second sub-reagent (i.e., a cell suspension) and release the second sub-reagent into the second sample inlet of the microfluidic chip 300. A third sample inlet unit 3005 is connected to the third sample inlet of the microfluidic chip 300 and is configured to store a third sub-reagent (i.e., a biochemical reagent) and release the third sub-reagent into the third sample inlet of the microfluidic chip 300. The first sample dispensing unit 3006 of the sample dispensing unit 3002 is configured to receive and store non-target droplets, and the second sample dispensing unit 3007 of the sample dispensing unit 3002 is configured to receive and store target droplets.

[0150] The first sample injection unit 3003 of the cartridge device 3000 includes a sample injection port 3003A, a first storage cavity 3003B, and a second storage cavity 3003C; the second sample injection unit 3004 includes a sample injection port 3004A, a first storage cavity 3004B, and a second storage cavity 3004C; and the third sample injection unit 3005 includes a sample injection port 3005A, a first storage cavity 3005B, and a second storage cavity 3005C. The structures of the first sample injection units 3003, 3004, and 3005 of the cartridge device 3000 are completely identical to those of the first sample injection unit 1003 of the cartridge device 1000. Therefore, the first sample injection units 3003, 3004, and 3005 of the cartridge device 3000 have the same technical effects as the first sample injection unit 1003 of the cartridge device 1000. For the sake of simplicity, their structure and technical effects will not be repeated here. The first sample dispensing unit 3006 of the box device 3000 includes a sample dispensing hole 3006A, a third storage cavity 3006B, and a fourth storage cavity 3006C. The second sample dispensing unit 3007 of the box device 3000 includes a sample dispensing hole 3007A, a third storage cavity 3007B, and a fourth storage cavity 3007C. The first sample dispensing unit 3006 and the second sample dispensing unit 3007 have the same structure. Except for the relative positions of the fourth storage cavity and the sample dispensing hole, the structure of the first sample dispensing unit 3006 and the second sample dispensing unit 3007 of the box device 3000 is basically the same as the structure of the sample dispensing unit 1006 of the box device 1000. Therefore, the structure and technical effect of each sample dispensing unit of the box device 3000 can be referenced to the structure and technical effect of the sample dispensing unit 1006 of the box device 1000. In the housing device 3000, taking the first sample dispensing unit 3006 as an example, the orthographic projection of the fourth storage cavity 3006C on the housing device 3000 falls within the orthographic projection of the sample dispensing hole 3006A on the housing device 3000.

[0151] The housing device 3000 also includes a first mounting area 3008 and a second mounting area 3009. The first mounting area 3008 is configured to mount an optical recognition device, and the second mounting area 3009 is configured to mount a driving electrode device. The optical recognition device and the driving electrode device are used in conjunction with the microfluidic chip 300 to achieve the sorting of target droplets. The first sample dispensing unit 3006 and the second sample dispensing unit 3007 are located between the sample injection unit 3001 and the first mounting area 3008 and the second mounting area 3009. Similar to the microfluidic chip 300, this arrangement can reduce the size of the housing device 3000, making it more miniaturized and saving costs.

[0152] The general process of preparing droplets and sorting target droplets using the housing device 3000 and the microfluidic chip 300 can be described as follows:

[0153] (1) A first fluid, cell suspension and biochemical reagent are pre-added to the first injection unit 3003, the second injection unit 3004 and the third injection unit 3005 respectively. The first fluid is an oil phase and may contain surfactants.

[0154] (2) The inlet port 3003A of the first inlet unit 3003, the inlet port 3004A of the second inlet unit 3004 and the inlet port 3005A of the third inlet unit 3005 of the box device 3000 are connected to the corresponding flow pumps through flexible pipes, and the flow rate of fluid injected into the inlet unit is controlled by adjusting the pressure of the flow pump.

[0155] (3) The first fluid in the first injection unit 3003 flows into the first injection port of the microfluidic chip 300 through the injection port 3003A, the first storage chamber 3003B, and the second storage chamber 3003C; the cell suspension in the second injection unit 3004 flows into the second injection port of the microfluidic chip 300 through the injection port 3004A, the first storage chamber 3004B, and the second storage chamber 3004C; the biochemical reagent in the third injection unit 3005 flows into the third injection port of the microfluidic chip 300 through the injection port 3005A, the first storage chamber 3005B, and the second storage chamber 3005C. Note that the microfluidic chip 300 can be filled with the first fluid of the oil phase first, and then the cell suspension and biochemical reagent can be injected.

[0156] (4) The first fluid, cell suspension, and biochemical reagents converge at the confluence point 304 of the microfluidic chip 300 to form droplets containing single cells. These droplets are then sorted at the sorting channel 305 and enter corresponding sub-collection sections. Non-target droplets are collected in the first collection section 3061, while target droplets (including single target cells) are collected in the second collection section 3062. Non-target droplets in the first collection section 3061 flow into the first sample outlet unit 3006 of the housing device 3000 via the sample outlet, while target droplets in the second collection section 3062 flow into the second sample outlet unit 3007 of the housing device 3000 via the sample outlet. The first sample outlet unit 3006 and the second sample outlet unit 3007 can store the corresponding droplets or, as needed, transfer them to other devices.

[0157] The housing device 3000 is adapted to the microfluidic chip 300 to jointly realize the preparation of droplets, including single cells, and the sorting of target droplets. Since the droplets are completely confined within the sealed housing device 3000 and microfluidic chip 300 before and after sorting, this housing device 3000 provides a sterile operating environment. Furthermore, the presence of the housing device 3000 makes the system composed of the housing device 3000 and microfluidic chip 300 simpler, more convenient, and easier to carry.

[0158] Figure 8 A schematic diagram of a housing device 4000 according to another embodiment of the present disclosure is shown, wherein (a) is a front view of the housing device 4000, (b) is a right view of the housing device 4000, (c) is a top view of the housing device 4000, and (d) is an axial view of the housing device 4000. The housing device 4000 is adapted to the present application. Figure 2 The microfluidic chip 400 shown, when combined with other components, can be used for cascade sorting of target droplets to obtain target droplets containing different types of target cells. The cascade sorting process of the droplets can be found in the description of the microfluidic chip 400.

[0159] The cartridge device 4000 includes an injection unit 4001 and an outlet unit 4002. The injection unit 4001 is connected to the injection port of the microfluidic chip 400 and is configured to store a first reagent and release the first reagent into the injection port of the microfluidic chip 400. The outlet unit 4002 is connected to the outlet port of the microfluidic chip 400 and is configured to receive and store a second reagent processed by the microfluidic chip 400 and flowing into the outlet unit 4002 from the outlet port of the microfluidic chip 400. The second reagent includes target droplets and non-target droplets, wherein the target droplets include: target droplets including a single type A target cell, target droplets including a single type B target cell, and target droplets including a single type C target cell; and non-target droplets include droplets including type D non-target cells. The sample injection unit 4001 includes a first sample injection unit 4003, a second sample injection unit 4004, and a third sample injection unit 4005. The sample dispensing unit 4002 includes a first sample dispensing unit 4006 and second sample dispensing units 4007, 4008, and 4009. The sample inlet of the microfluidic chip 400 includes a first sample inlet and a second sample inlet located at two third receiving portions 401, and a third sample inlet located at a fourth receiving portion 402. The first injection unit 4003 is connected to the first injection port of the microfluidic chip 400. The first injection unit 4003 is configured to store the first sub-reagent (i.e., the first fluid) and release the first sub-reagent into the first injection port of the microfluidic chip 400. The second injection unit 4004 is connected to the second injection port of the microfluidic chip 400. The second injection unit 4004 is configured to store the first sub-reagent (i.e., the first fluid) and release the first sub-reagent into the second injection port of the microfluidic chip 400. The third injection unit 4005 is connected to the third injection port of the microfluidic chip 400. The third injection unit 4005 is configured to store the second sub-reagent (i.e., droplets including single cells) and release the second sub-reagent into the third injection port of the microfluidic chip 400. The first sampling unit 4006 of the sampling unit 4002 is configured to receive and store non-target droplets, and the second sampling units 4007-4009 of the sampling unit 4002 are configured to receive and store target droplets including a single type A cell, a target droplet including a single type B cell, and a target droplet including a single type C cell, respectively.

[0160] The first sample injection unit 4003 of the cartridge device 4000 includes a sample injection port 4003A, a first storage cavity 4003B, and a second storage cavity 4003C; the second sample injection unit 4004 includes a sample injection port 4004A, a first storage cavity 4004B, and a second storage cavity 4004C; and the third sample injection unit 4005 includes a sample injection port 4005A, a first storage cavity 4005B, and a second storage cavity 4005C. The structures of the first sample injection units 4003, 4004, and 4005 of the cartridge device 4000 are completely identical to those of the first sample injection unit 1003 of the cartridge device 1000. Therefore, the first sample injection units 4003, 4004, and 4005 of the cartridge device 4000 have the same technical effects as the first sample injection unit 1003 of the cartridge device 1000. For the sake of simplicity, their structure and technical effects will not be repeated here. The first sample dispensing unit 4006 of the box device 4000 includes a sample dispensing hole 4006A, a third storage cavity 4006B, and a fourth storage cavity 4006C; the second sample dispensing unit 4007 of the box device 4000 includes a sample dispensing hole 4007A, a third storage cavity 4007B, and a fourth storage cavity 4007C; the second sample dispensing unit 4008 of the box device 4000 includes a sample dispensing hole 4008A, a third storage cavity 4008B, and a fourth storage cavity 4008C; the second sample dispensing unit 4009 of the box device 4000 includes a sample dispensing hole 4009A, a third storage cavity 4009B, and a fourth storage cavity 4009C. The first sample dispensing unit 4006 and the second sample dispensing units 4007-4009 have identical structures. Except for the relative positions of the fourth storage cavity and the sample outlet, the structures of the first sample outlet unit 4006 and the second sample outlet units 4007-4009 of the box device 4000 are basically the same as those of the sample outlet unit 1006 of the box device 1000. Therefore, the structure and technical effects of each sample outlet unit of the box device 4000 can be referenced from the structure and technical effects of the sample outlet unit 1006 of the box device 1000. In the box device 4000, taking the first sample outlet unit 4006 as an example, the orthographic projection of the fourth storage cavity 4006C on the box device 4000 falls within the orthographic projection of the sample outlet 4006A on the box device 4000.

[0161] The housing device 4000 also includes a first mounting area and a second mounting area located between the sample introduction unit 4001 and the sample dispensing unit 4002. The first mounting area is configured to mount multiple optical recognition devices, and the second mounting area is configured to mount multiple driving electrode devices. The optical recognition devices and driving electrode devices are used to cooperate with the microfluidic chip 400 to achieve cascaded sorting of target droplets. Specifically, the first mounting area includes a first sub-mounting unit 4010, a second sub-mounting unit 4011, and a third sub-mounting unit 4012, and the second mounting area includes a fourth sub-mounting unit 4013, a fifth sub-mounting unit 4014, and a sixth sub-mounting unit 4015. The first sub-mounting unit 4010 and the fourth sub-mounting unit 4013 are associated, the second sub-mounting unit 4011 and the fifth sub-mounting unit 4014 are associated, and the third sub-mounting unit 4012 and the sixth sub-mounting unit 4015 are associated.

[0162] The general process of cascading sorting of target droplets using the housing device 4000 and the microfluidic chip 400 can be described as follows:

[0163] (1) A first fluid is pre-added to the first injection unit 4003 and the second injection unit 4004 respectively, and a droplet containing a single cell is pre-added to the third injection unit 4005. The droplet can be prepared by the above-mentioned housing device 1000 and microfluidic chip 100. The first fluid is an oil phase, which may be mixed with surfactants.

[0164] (2) The inlet port 4003A of the first inlet unit 4003, the inlet port 4004A of the second inlet unit 4004 and the inlet port 4005A of the third inlet unit 4005 of the box device 4000 are connected to the corresponding flow pumps through flexible pipes, and the flow rate of fluid injected into the inlet unit is controlled by adjusting the pressure of the flow pump.

[0165] (3) The first fluid in the first injection unit 4003 flows into the first injection port of the microfluidic chip 400 through the injection port 4003A, the first storage chamber 4003B, and the second storage chamber 4003C; the first fluid in the second injection unit 4004 flows into the second injection port of the microfluidic chip 400 through the injection port 4004A, the first storage chamber 4004B, and the second storage chamber 4004C; the droplet in the third injection unit 4005 flows into the third injection port of the microfluidic chip 400 through the injection port 4005A, the first storage chamber 4005B, and the second storage chamber 4005C. Note that the microfluidic chip 400 can be filled with the first fluid of the oil phase first, and then the droplet is injected.

[0166] (4) The droplets are sorted at the sorting channel 403 of the microfluidic chip 400 and enter the corresponding sub-collection section. Non-target droplets including type D non-target cells are collected in the first collection section 405, target droplets including a single type A target cell are collected in the first sub-collection section 4061, target droplets including a single type B target cell are collected in the second sub-collection section 4062, and target droplets including a single type C target cell are collected in the third sub-collection section 4063. Non-target droplets in the first collection section 405 flow into the first dispensing unit 4006 of the container device 4000 through the dispensing port. Target droplets in the first sub-collection section 4061 flow into the second dispensing unit 4007 of the container device 4000 through the dispensing port. Target droplets in the second sub-collection section 4062 flow into the second dispensing unit 4008 of the container device 4000 through the dispensing port. Target droplets in the third sub-collection section 4063 flow into the second dispensing unit 4009 of the container device 4000 through the dispensing port. The first dispensing unit 4006 and the second dispensing units 4007-4009 can store the corresponding droplets or transfer them to other devices as needed.

[0167] The housing device 4000 is adapted to the microfluidic chip 400 to jointly achieve cascaded sorting of target droplets. Using this housing device 4000 and microfluidic chip 400, three different types of target cells can be screened in a single sorting process, significantly improving the speed and efficiency of cell sorting. Moreover, compared to using three different microfluidic chips to screen three different types of target cells separately, the embodiments of this disclosure only require one housing device 4000 and microfluidic chip 400 to achieve the sorting of three different types of target cells, greatly reducing the number of microfluidic chips and housing devices required, thereby saving production costs.

[0168] The housing device 4000 can be slightly modified to obtain the housing device 4000', which can be adapted to this application. Figure 3 The microfluidic chip 400' is shown. The modified cartridge device 4000' differs from the cartridge device 4000 only in the number of dispensing units; other components remain unchanged. In the cartridge device 4000, there is one first dispensing unit 4006 and three second dispensing units. In the cartridge device 4000', there is one first dispensing unit 4006 and one second dispensing unit.

[0169] The first three steps of cascading sorting of target droplets using the housing device 4000' and the microfluidic chip 400' are exactly the same as the first three steps (1)-(3) of cascading sorting of target droplets using the housing device 4000 and the microfluidic chip 400 mentioned above. For the sake of brevity, they will not be repeated here. The description will begin from the fourth step below.

[0170] (4) Droplets are sorted at the sorting channel 403 of the microfluidic chip 400' and enter the corresponding sub-collection section. Non-target droplets, including type F non-target cells, are collected in the first collection section 405' via the first branch 4031A, the second branch 4031B, and the third branch 4031C. Target droplets, including single type E target cells, are collected in the second collection section 406. Non-target droplets in the first collection section 405' flow into the first sample outlet of the cartridge device 4000' via the sample outlet. Target droplets in the second collection section 406 flow into the second sample outlet of the cartridge device 4000' via the sample outlet. The first and second sample outlets can store the corresponding droplets or transfer them to other devices as needed.

[0171] The housing device 4000' and the microfluidic chip 400' are adapted to jointly achieve cascaded sorting of target droplets. By using the housing device 4000' and the microfluidic chip 400' to perform multiple cascaded sorting of droplets, target droplets and non-target droplets that are difficult to distinguish can be separated, which greatly improves the purity of the finally collected target droplets and reduces or even eliminates the possibility of non-target droplets being included in the collected target droplets.

[0172] Figure 9 A schematic diagram of a housing device 5000 according to another embodiment of the present disclosure is shown, wherein (a) is a front view of the housing device 5000, (b) is a right view of the housing device 5000, (c) is a top view of the housing device 5000, and (d) is an axial view of the housing device 5000. The housing device 5000 is adapted to this application. Figure 4 The microfluidic chip 500 shown, when combined with the microfluidic chip, can be used to sort droplets of different sizes. The specific droplet sorting process can be found in the description of the microfluidic chip 500.

[0173] The cartridge device 5000 includes a sample inlet unit 5001 and a sample outlet unit 5002. The sample inlet unit 5001 is connected to the sample inlet of the microfluidic chip 500 and configured to store a first reagent and release it into the sample inlet of the microfluidic chip 500. The first reagent is a large number of droplets, at least a portion of which includes single cells. The sample outlet unit 5002 is connected to the sample outlet of the microfluidic chip 500 and configured to receive and store a second reagent processed by the microfluidic chip 500 and flowing into the sample outlet unit 5002 from the sample outlet of the microfluidic chip 500. The second reagent includes two types of droplets with different particle sizes. The sample inlet unit 5001 includes a sample inlet unit 5003, and the sample outlet unit 5002 includes a first sample outlet unit 5004 and a second sample outlet unit 5005. The sample introduction unit 5003 is connected to the sample inlet of the microfluidic chip 500. The sample introduction unit 5003 is configured to store droplets and release droplets into the sample inlet of the microfluidic chip 500. The first sample dispensing unit 5004 of the sample dispensing unit 5002 is configured to receive and store droplets with a smaller particle size, and the second sample dispensing unit 5005 of the sample dispensing unit 5002 is configured to receive and store droplets with a larger particle size.

[0174] The sample inlet unit 5003 of the cartridge device 5000 includes a sample inlet 5003A, a first storage cavity 5003B, and a second storage cavity 5003C. The sample inlet unit 5003 of the cartridge device 5000 has the same structure as the first sample inlet unit 1003 of the cartridge device 1000, therefore, the sample inlet unit 5003 of the cartridge device 5000 has the same technical effect as the first sample inlet unit 1003 of the cartridge device 1000. For the sake of simplicity, its structure and technical effect will not be repeated here. The first sample outlet unit 5004 of the cartridge device 5000 includes a sample outlet 5004A, a third storage cavity 5004B, and a fourth storage cavity 5004C; the second sample outlet unit 5005 of the cartridge device 5000 includes a sample outlet 5005A, a third storage cavity 5005B, and a fourth storage cavity 5005C. The first sample outlet unit 5004 and the second sample outlet unit 5005 have the same structure. Except for the relative positions of the fourth storage cavity and the sample outlet, the structures of the first sample outlet unit 5004 and the second sample outlet unit 5005 of the box device 5000 are basically the same as those of the sample outlet unit 1006 of the box device 1000. Therefore, the structure and technical effects of each sample outlet unit of the box device 5000 can be referenced from the structure and technical effects of the sample outlet unit 1006 of the box device 1000. In the box device 5000, taking the first sample outlet unit 5004 as an example, the orthographic projection of the fourth storage cavity 5004C on the box device 5000 falls within the orthographic projection of the sample outlet 5004A on the box device 5000.

[0175] The general process of sorting target droplets using the housing device 5000 and the microfluidic chip 500 can be described as follows:

[0176] (1) A droplet containing a single cell is pre-added to the sample introduction unit 5003. The droplet can be prepared by the aforementioned housing device 1000 and microfluidic chip 100. The first fluid is an oil phase, which may be mixed with a surfactant.

[0177] (2) The injection port 5003A of the injection unit 5003 of the box device 5000 is connected to the flow pump through a flexible pipe, and the flow rate of fluid injected into the injection unit is controlled by adjusting the pressure of the flow pump.

[0178] (3) The droplets in the injection unit 5003 flow into the injection port of the microfluidic chip 500 through the injection port 5003A, the first storage chamber 5003B and the second storage chamber 5003C.

[0179] (4) The droplets flow within the main flow channel 503 of the microfluidic chip 500 and are sorted and enter the corresponding collection section under the action of inertial force. At the bifurcation point at the end of the main flow channel 503, the smaller first-type droplets are subject to less inertial force and thus enter the first sorting flow channel 504 along the extension direction of the main flow channel 503, and then flow into the first collection section 507. The larger second-type droplets are subject to greater inertial force and are thrown out of the main flow channel 503 under the action of less inertial force and enter the second sorting flow channel 505, and finally flow into the second collection section 508. The first-type droplets in the first collection section 507 flow into the first sample dispensing unit 5004 of the cartridge device 5000 through the sample outlet, and the second-type droplets in the second collection section 508 flow into the second sample dispensing unit 5005 of the cartridge device 5000 through the sample outlet. The first sample dispensing unit 5004 and the second sample dispensing unit 5005 can store the corresponding droplets or transfer these droplets to other devices as needed.

[0180] The housing device 5000 is adapted to the microfluidic chip 500 to sort droplets of different sizes. The housing device 5000 eliminates the need for areas for mounting optical recognition devices and driving electrode devices, and the microfluidic chip 500 also eliminates the need for optical recognition devices and driving electrode devices. Instead, it relies solely on the shape of the main flow channel 503 to separate droplets of different sizes. Because no optical recognition devices and driving electrode devices are required, the size of both the housing device 5000 and the microfluidic chip 500 can be reduced, thus saving on production costs.

[0181] According to another aspect of this disclosure, a microfluidic device is provided. Figure 10A block diagram of the microfluidic device is shown. The microfluidic device includes a microfluidic chip as described in any of the preceding embodiments and a housing device as described in any of the preceding embodiments, the microfluidic chip and the corresponding housing device being assembled together. Since the microfluidic device can have essentially the same technical effects as the microfluidic chip and housing device described in the preceding embodiments, for the sake of brevity, the technical effects of the microfluidic device will not be repeated here.

[0182] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, areas, layers, and / or parts, these elements, components, areas, layers, and / or parts should not be limited by these terms. These terms are used only to distinguish one element, component, area, layer, or part from another. Therefore, the first element, component, area, layer, or part discussed above may be referred to as a second element, component, area, layer, or part without departing from the teachings of this disclosure.

[0183] Spatial relative terms such as “row,” “column,” “below,” “above,” “left,” “right,” etc., may be used herein for ease of description to describe the relationship between one element or feature illustrated in the figures and another element(s). It will be understood that these spatial relative terms are intended to cover different orientations of the device in use or operation, in addition to those depicted in the figures. For example, if the device in the figure is flipped, then an element described as “below other elements or features” will be oriented “above other elements or features.” Thus, the exemplary term “below” can cover both orientations above and below. Devices may be oriented in other ways (rotated 90 degrees or otherwise) and the spatial relative descriptors used herein will be interpreted accordingly. Additionally, it will be understood that when a layer is referred to as “between two layers,” it may be the only layer between those two layers, or there may be one or more intermediate layers.

[0184] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprising” and / or “including”, when used in this specification, specify the presence of the 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. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. In the description of this specification, references to the terms “one embodiment,” “another embodiment,” etc., mean that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this disclosure. The illustrative expressions of the foregoing terms in this specification do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of the different embodiments or examples, without contradiction.

[0185] It will be understood that when a component or layer is referred to as "on another component or layer," "connected to another component or layer," "coupled to another component or layer," or "adjacent to another component or layer," it may be directly on another component or layer, directly connected to another component or layer, directly coupled to another component or layer, or directly adjacent to another component or layer, or there may be intermediate components or layers. Conversely, when a component is referred to as "directly on another component or layer," "directly connected to another component or layer," "directly coupled to another component or layer," or "directly adjacent to another component or layer," no intermediate components or layers exist. However, in any case, "on" or "directly on" should not be interpreted as requiring a layer to completely cover the layer below.

[0186] Embodiments of this disclosure are described herein with reference to illustrative illustrations (and intermediate structures) of idealized embodiments. Therefore, variations in the illustrated shapes should be expected, for example, as a result of manufacturing techniques and / or tolerances. Consequently, embodiments of this disclosure should not be construed as limited to the specific shapes of the regions illustrated herein, but should include, for example, shape deviations due to manufacturing processes. Thus, the regions illustrated are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of a device and are not intended to limit the scope of this disclosure.

[0187] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the relevant field and / or the context of this specification, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0188] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A microfluidic chip, comprising: A first receiving section is configured to receive a first fluid; A second containment is configured to contain a second fluid, the second fluid comprising a cell suspension; The conveying channel includes a first conveying channel and a second conveying channel, the first conveying channel being connected to the first receiving portion and the second conveying channel being connected to the second receiving portion, the first conveying channel and the second conveying channel intersecting and communicating with each other at a confluence point, and the shape of the conveying channel being designed such that the first fluid and the second fluid converge at the confluence point; A sorting channel, located downstream of the conveying channel, includes a first sorting channel and a second sorting channel; and A collection section, located downstream of the sorting channel, includes a first collection section and a second collection section. The first collection section is connected to the first sorting channel, and the second collection section is connected to the second sorting channel. The first transport channel includes a first sub-section, a third sub-section, and a second sub-section including the confluence point and located between the first and third sub-sections, arranged along a first direction. The second transport channel includes a first sub-channel, a third sub-channel, and a second sub-channel located between the first and third sub-channels, arranged along a second direction. The second sub-channel includes the confluence point. The width of a first cross-section of the second sub-section at the confluence point is greater than one times the particle size of a single cell and less than twice the particle size of a single cell. The width of a second cross-section of the second sub-channel is greater than one times the particle size of a single cell and less than twice the particle size of a single cell. The first cross-section is perpendicular to the first direction, and the second cross-section is perpendicular to the second direction. The cell suspension includes the single cells. The second accommodating portion includes a first sub-accommodating portion configured to accommodate the cell suspension and a second sub-accommodating portion configured to accommodate biochemical reagents. The first sub-channel includes a first branch and a second branch. The first branch communicates with the first sub-accommodating portion, and the second branch communicates with the second sub-accommodating portion. The areas of the second cross-sections of the first branch and the second branch are both larger than the area of ​​the second cross-section of the second sub-channel.

2. The microfluidic chip according to claim 1, wherein, The area of ​​the first cross-section of the first sub-part gradually increases along a first direction away from the confluence point, and the area of ​​the first cross-section of the third sub-part gradually increases along a first direction away from the confluence point, and... The areas of the second cross-sections of the first sub-channel and the second sub-channel gradually increase along a second direction away from the confluence point, and the area of ​​the second cross-section of the third sub-channel gradually increases along a second direction away from the confluence point.

3. The microfluidic chip according to claim 1, wherein, The beginning of the first sorting channel and the beginning of the second sorting channel are both connected to the end of the conveying channel. The end of the first sorting channel is connected to the first collection section and the end of the second sorting channel is connected to the second collection section. The first sorting channel and the second sorting channel bend from the end of the conveying channel toward the confluence point, and the first collection section and the second collection section are located between the confluence point and the end of the conveying channel.

4. The microfluidic chip according to claim 1, wherein, The sorting channel also includes at least two connecting channels. The second sorting channel includes at least two cascaded branches, and a connecting channel is provided between any two adjacent branches of the at least two cascaded branches and the two adjacent branches are connected via the connecting channel. The beginning of the first sorting channel is connected to the end of the conveying channel, and the end of the first sorting channel is connected to the first collecting section. The first sorting channel is adjacent to the first-level branch of the at least two cascaded branches, and a connecting channel is provided between the first sorting channel and the first-level branch, with the first sorting channel and the first-level branch connected via the connecting channel. The second collection unit includes at least two sub-collection units, the cascaded branches correspond one-to-one with the sub-collection units, and one of the cascaded branches is connected to a corresponding one of the sub-collection units.

5. The microfluidic chip according to claim 4, wherein, The second sorting channel includes cascaded first-level branches, second-level branches, and third-level branches; the at least two connecting channels include a first connecting channel, a second connecting channel, and a third connecting channel; and the second collection section includes a first sub-collection section, a second sub-collection section, and a third sub-collection section. The first sorting channel is connected to the first-level branch via the first connecting channel, the first-level branch is connected to the second-level branch via the second connecting channel, and the second-level branch is connected to the third-level branch via the third connecting channel; and The end of the first-level branch is connected to the first sub-collection unit, the end of the second-level branch is connected to the second sub-collection unit, and the end of the third-level branch is connected to the third sub-collection unit.

6. The microfluidic chip according to claim 5, wherein, The second connecting channel is closer to the collection part in the second direction than the first connecting channel, and the third connecting channel is closer to the collection part in the second direction than the second connecting channel.

7. The microfluidic chip according to claim 5 further includes two third receiving portions, wherein, The beginning of the first-level branch and the beginning of the second-level branch are respectively connected to one of the two third accommodating portions, which are configured to accommodate the first fluid.

8. The microfluidic chip according to claim 1, wherein, The sorting channel also includes at least two connecting channels. The first sorting channel includes at least two cascaded branches, and a connecting channel is provided between any two adjacent branches of the at least two cascaded branches, and the two adjacent branches are connected via the connecting channel. The ends of the at least two cascaded branches are all connected to the first collecting section; and The beginning of the second sorting channel is connected to the last branch of the first sorting channel via a connecting channel, and the end of the second sorting channel is connected to the second collection section.

9. The microfluidic chip according to claim 1, wherein, The sorting channel further includes a main channel, which is spiral-shaped in the plane of the microfluidic chip. The end of the main channel is connected to the first sorting channel and the second sorting channel. The first sorting channel is configured to screen a first droplet, and the second sorting channel is configured to screen a second droplet. The first droplet screened by the first sorting channel and the second droplet screened by the second sorting channel have different particle sizes.

10. The microfluidic chip according to claim 2, wherein, The area of ​​the first cross-section of both the first sub-part and the third sub-part is greater than the area of ​​the first cross-section of the second sub-part.

11. The microfluidic chip according to claim 10, in, The first end of the first sub-channel is connected to the second receiving portion, the second end of the first sub-channel is connected to the first end of the second sub-channel, the second end of the second sub-channel is connected to the first end of the third sub-channel, and both the second end of the second sub-channel and the first end of the third sub-channel are located at the confluence point. Wherein, the area of ​​the second cross-section of both the first sub-channel and the third sub-channel is greater than the area of ​​the second cross-section of the second sub-channel.

12. The microfluidic chip according to claim 11, wherein, The area of ​​the second cross-section of the third sub-channel gradually increases along the direction from the first end to the second end of the third sub-channel.

13. The microfluidic chip according to claim 1, wherein, The inner wall surface of the conveying channel is hydrophobic.

14. The microfluidic chip according to claim 1, wherein, The outlines of the first and second receiving portions include four chamfers, the chamfers being arc-shaped.

15. The microfluidic chip according to claim 1, wherein, Both the first and second accommodating portions are provided with a filtration structure, which includes multiple microstructures. The gap between any two adjacent microstructures is greater than one time the particle size of a single cell in the cell suspension and less than twice the particle size of the single cell.

16. The microfluidic chip according to any one of claims 1-15, further comprising an inlet and an outlet, wherein, The sample inlet is arranged in the first and second accommodating parts, and the sample outlet is arranged in the collecting part.

17. A housing device configured for use with a microfluidic chip according to any one of claims 1-16, the microfluidic chip comprising an inlet and an outlet, wherein, The housing device includes: A receiving cavity configured to receive the microfluidic chip according to any one of claims 1-16; A sample introduction unit, connected to the sample inlet of the microfluidic chip, is configured to store a first reagent and release the first reagent into the sample inlet of the microfluidic chip; and A sample dispensing unit is connected to the sample dispensing port of the microfluidic chip. The sample dispensing unit is configured to receive and store a second reagent processed by the microfluidic chip and flowing into the sample dispensing unit from the sample dispensing port of the microfluidic chip. The sample injection unit includes a sample injection port and a first storage cavity. The sample injection port is a through hole and communicates with the first storage cavity. The sample injection port is recessed from the surface of the housing device into the interior of the housing device, and the first storage cavity is located on the side of the sample injection port away from the surface of the housing device.

18. The housing device according to claim 17, wherein, The first storage cavity is located inside the housing device, and the orthographic projection of the sample inlet on the housing device falls within the orthographic projection of the first storage cavity on the housing device.

19. The housing device according to claim 17, wherein, The sample injection unit further includes a second storage cavity, which is located on the side of the first storage cavity away from the sample injection port and communicates with the first storage cavity. The second storage cavity includes a first opening communicating with the first storage cavity and a second opening opposite to the first opening. The orthographic projection of the second opening on the housing device falls within the orthographic projection of the first opening on the housing device.

20. The housing device according to claim 19, wherein, The orthographic projection of the second opening of the second storage cavity onto the housing device falls within the orthographic projection of the sample inlet onto the housing device.

21. The housing device according to claim 17, wherein, The sample dispensing unit includes a sample dispensing hole and a third storage cavity. The sample dispensing hole is a through hole and communicates with the third storage cavity. The sample dispensing hole is recessed from the surface of the box device into the interior of the box device, and the third storage cavity is located on the side of the sample dispensing hole away from the surface of the box device.

22. The housing device according to claim 21, wherein, The third storage cavity is located inside the box assembly, and the orthographic projection of the sample outlet on the box assembly falls within the orthographic projection of the third storage cavity on the box assembly.

23. The housing device according to claim 21, wherein, The sample dispensing unit further includes a fourth storage cavity, which is located on the side of the third storage cavity away from the sample dispensing hole and is in communication with the third storage cavity.

24. The housing device according to claim 23, wherein, The orthographic projection of the fourth storage cavity onto the housing device and the orthographic projection of the sample outlet onto the housing device overlap by at most a portion.

25. The housing device according to claim 23, wherein, The orthographic projection of the fourth storage cavity onto the housing device falls within the orthographic projection of the sample outlet hole onto the housing device.

26. The housing device according to any one of claims 17-25, wherein, The sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid, a cell suspension, and a biochemical reagent. The first injection unit is connected to the first injection port of the microfluidic chip, and is configured to store the first fluid and release the first fluid into the first injection port of the microfluidic chip; the second injection unit is connected to the second injection port of the microfluidic chip, and is configured to store the cell suspension and release the cell suspension into the second injection port of the microfluidic chip; the third injection unit is connected to the third injection port of the microfluidic chip, and is configured to store the biochemical reagent and release the biochemical reagent into the third injection port of the microfluidic chip.

27. The housing device according to any one of claims 17-25, further comprising a first mounting region and a second mounting region, wherein, The first mounting area is configured to mount an optical recognition device, and the second mounting area is configured to mount a driving electrode device.

28. The housing device according to claim 27, wherein, The sample introduction unit includes a first sample introduction unit and a second sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet and a second sample inlet. The first reagent includes a first fluid and a droplet comprising a single cell. The first sample injection unit is connected to the first sample inlet of the microfluidic chip, and is configured to store the first fluid and release the first fluid into the first sample inlet of the microfluidic chip; the second sample injection unit is connected to the second sample inlet of the microfluidic chip, and is configured to store the droplet containing a single cell and release the droplet containing a single cell into the second sample inlet of the microfluidic chip; and The sample dispensing unit includes a first sample dispensing unit, a second sample dispensing unit, and a third sample dispensing unit located between the first sample dispensing unit and the second sample dispensing unit. The second reagent includes a first droplet and a second droplet. The third sample dispensing unit is configured to receive and store the first droplet, and the first sample dispensing unit and the second sample dispensing unit are configured to receive and store the second droplet.

29. The housing device according to claim 27, wherein, The sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid, a cell suspension, and a biochemical reagent. The first injection unit is connected to the first injection port of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first injection port of the microfluidic chip. The second injection unit is connected to the second injection port of the microfluidic chip and is configured to store the cell suspension and release the cell suspension into the second injection port of the microfluidic chip. The third injection unit is connected to the third injection port of the microfluidic chip and is configured to store the biochemical reagent and release the biochemical reagent into the third injection port of the microfluidic chip. The sample dispensing unit includes a first sample dispensing unit and a second sample dispensing unit, and the second reagent includes a first droplet and a second droplet. The first sample dispensing unit is configured to receive and store the first droplet, and the second sample dispensing unit is configured to receive and store the second droplet.

30. The housing device according to claim 29, wherein, The first sample dispensing unit and the second sample dispensing unit are located between the sample injection unit and the first installation area and the second installation area.

31. The housing device according to claim 27, wherein, The first installation area and the second installation area are located between the sample injection unit and the sample dispensing unit. The first installation area includes a first sub-installation unit, a second sub-installation unit, and a third sub-installation unit. The second installation area includes a fourth sub-installation unit, a fifth sub-installation unit, and a sixth sub-installation unit. The first sub-installation unit and the fourth sub-installation unit are associated, the second sub-installation unit and the fifth sub-installation unit are associated, and the third sub-installation unit and the sixth sub-installation unit are associated.

32. The housing device according to claim 31, wherein, The sample introduction unit includes a first sample introduction unit, a second sample introduction unit, and a third sample introduction unit. The sample inlet of the microfluidic chip includes a first sample inlet, a second sample inlet, and a third sample inlet. The first reagent includes a first fluid and a droplet comprising a single cell. The first injection unit is connected to the first injection port of the microfluidic chip and is configured to store the first fluid and release the first fluid into the first injection port of the microfluidic chip. The second injection unit is connected to the second injection port of the microfluidic chip and is configured to store the first fluid and release the first fluid into the second injection port of the microfluidic chip. The third injection unit is connected to the third injection port of the microfluidic chip and is configured to store the droplet containing a single cell and release the droplet containing the single cell into the third injection port of the microfluidic chip. The sample dispensing unit includes a first sample dispensing unit and a second sample dispensing unit, and the second reagent includes a first droplet and a second droplet. The first sample dispensing unit is configured to receive and store the first droplet, and the second sample dispensing unit is configured to receive and store the second droplet.

33. The housing device according to claim 32, wherein, The number of the first sampling unit is one, and the number of the second sampling unit is three.

34. The housing device according to claim 32, wherein, The number of the first sampling unit is one, and the number of the second sampling unit is one.

35. The housing device according to any one of claims 17-25, wherein, The cartridge device includes a sample inlet unit and two sample outlet units. The second reagent includes a first droplet and a second droplet, the first droplet and the second droplet having different particle sizes. One of the two sample outlet units is configured to receive and store the first droplet, and the other of the two sample outlet units is configured to receive and store the second droplet.

36. A microfluidic device comprising a microfluidic chip as claimed in any one of claims 1-16 and a housing device as claimed in any one of claims 17-35, wherein, The microfluidic chip is assembled with the housing device.

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