Microfluidic chips and microfluidic systems

Abstract

The application discloses a micro-fluidic chip and a micro-fluidic system, and relates to the technical field of single-cell analysis. The micro-fluidic chip comprises a first sample inlet module and a second control module. The first sample inlet module has a first detection position and a second detection position. The first sample inlet module is used for providing first particles and second particles. The first detection position is used for detecting the first particles. The second detection position is used for detecting the second particles. The first sample inlet module transports the detected first particles and second particles through a symmetrically arranged flow channel structure. In addition, the first detection position and the second detection position are symmetrically arranged, so as to shorten the time difference of the first particles and the second particles flowing to the pairing flow channel, and to improve the problem of hysteresis of any one of the first particles and the second particles in the pairing process.

Description

Technical Field

[0001] This application relates to the field of single-cell analysis technology, and in particular to a microfluidic chip and microfluidic system. Background Technology

[0002] In the fields of medical and life science research, single-cell analysis, with its unique advantage of revealing cellular heterogeneity, has become a key tool for understanding disease mechanisms, aiding early diagnosis, and advancing precision medicine. Single-cell isolation and precise sorting, as indispensable foundational steps in the single-cell analysis process, directly determine the reliability and depth of subsequent research. Microfluidic systems, with their high-throughput processing, ability to handle small sample volumes, and superior performance in precisely manipulating tiny particles, have distinguished themselves in the field of single-cell analysis and have gained widespread application and promotion. Specifically, single-cell analysis requires separating cell populations in tissues or body fluids into individual cells. To this end, a single-cell pairing system has been proposed, which includes a cell flow channel, a magnetic bead flow channel, a pairing flow channel, a buffer flow channel, an oil flow channel, a detection module, and corresponding microvalve. The cell flow channel contains a first liquid containing cells, and the magnetic bead flow channel contains a second liquid containing magnetic beads. When the detection module detects a cell or a magnetic bead, it controls the corresponding microvalve to cut off the flow of liquid in the corresponding flow channel, so that the single cell and the single magnetic bead remain in the pairing flow channel. Subsequently, the buffer solution provided by the buffer flow channel pushes the single cell and the single magnetic bead in the pairing flow channel into the oil flow channel, where they are encapsulated into droplets by the oil in the oil flow channel.

[0003] However, the above-mentioned single-cell pairing system has the following drawbacks: 1. During droplet generation, the lag in the flow of magnetic beads not only affects the droplet encapsulation effect but also leads to pairing failures. Additionally, the generated droplets may be too large, posing a risk of breakage and ultimately resulting in poor sequencing performance.

[0004] 2. During the pairing process, some cells may stick to the inner wall of the flow channel, resulting in cell loss and a decrease in cell recovery rate. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a microfluidic chip that helps to shorten the time difference between the flow of the first and second particles to the pairing channel, thereby improving the problem of lag in the pairing process of either the first or second particle.

[0006] This application also proposes a microfluidic system having the above-mentioned microfluidic chip.

[0007] The microfluidic chip according to a first aspect embodiment of this application includes: The first injection module includes a first flow channel, a second flow channel, a first buffer flow channel, a second buffer flow channel, a paired flow channel, and an oil flow channel. The first flow channel, the second flow channel, the first buffer flow channel, and the second buffer flow channel are all connected to the paired flow channel. The paired flow channel is connected to the oil flow channel. The first flow channel is used to allow a first liquid containing a first particle to pass through, and the second flow channel is used to allow a second liquid containing a second particle to pass through. The first control module includes a first micro valve corresponding to the first flow channel, a second micro valve corresponding to the second flow channel, and a paired micro valve corresponding to the paired flow channel. The first micro valve is used to control the opening and closing of the first flow channel, the second micro valve is used to control the opening and closing of the second flow channel, and the paired micro valve is used to control the opening and closing of the paired flow channel. The first buffer channel and the second buffer channel are located on both sides of the paired channel and are symmetrically arranged. A first delivery section is provided between the end of the first buffer channel and the paired channel, and a second delivery section is provided between the end of the second buffer channel and the paired channel. The first channel has a first outlet section, the end of which is connected to the first delivery section. The second channel has a second outlet section, the end of which is connected to the second delivery section. The first outlet section and the second outlet section are located on both sides of the paired channel and are symmetrically arranged. The first outlet section has a first detection position for detecting a first particle, and the second outlet section has a second detection position for detecting a second particle. The distance from the first detection position to the end of the first outlet section and the distance from the second detection position to the end of the second outlet section are the same.

[0008] The microfluidic chip according to the embodiments of this application has at least the following beneficial effects: during pairing, a first liquid containing a first particle is provided through a first channel, and a second liquid containing a second particle is provided through a second channel. When a first particle is detected at a first detection position, the detected first particle is stopped at a first liquid outlet section. When a second particle is detected at a second detection position, the first particle and the second particle are transported to the pairing channel to merge through a symmetrically arranged channel structure consisting of a first liquid outlet section, a first transport section, a first buffer channel, a second liquid outlet section, a second transport section, and a second buffer channel, and finally droplets are formed in the oil provided by the oil channel. In this design, the distance from the first detection position to the end of the first outlet section and the distance from the second detection position to the end of the second outlet section are the same. This ensures that the supply pressure of the first flow channel, the second flow channel, the first buffer solution flow channel, and the second buffer solution flow channel are the same. Combined with the aforementioned symmetrical flow channel structure, this helps to shorten the time difference between the first and second particles flowing to the pairing flow channel. That is, the first and second particles can arrive at the pairing flow channel and merge at approximately the same time, thereby improving the problem of lag between either the first or second particle during the pairing process. This not only improves the droplet encapsulation effect but also reduces the probability of pairing failure. Furthermore, it helps to reduce the problem of excessively large droplet volume caused by excessive spacing between the first and second particles, thus reducing the risk of droplet breakage.

[0009] According to some embodiments of this application, the end of the paired flow channel has an outlet section, the cross-sectional area of ​​which decreases along its own liquid outflow direction.

[0010] According to some embodiments of this application, the diameter of the end outlet of the outlet section is 20μm to 40μm.

[0011] According to some embodiments of this application, the oil flow channel includes two symmetrically arranged first branch flow channels, and the ends of the two first branch flow channels are respectively connected to the ends of the paired flow channels from both sides of the paired flow channel.

[0012] According to some embodiments of this application, the microfluidic chip further includes a collection channel connected to the end of the paired channel, and the centerline of the collection channel is collinear with the centerline of the paired channel.

[0013] According to some embodiments of this application, the microfluidic chip further includes a first waste liquid channel and a first waste liquid microvalve disposed corresponding to the first waste liquid channel. The first waste liquid channel is connected to the end of the paired channel away from the oil channel. The first waste liquid microvalve is used to control the opening and closing of the first waste liquid channel.

[0014] According to some embodiments of this application, the microfluidic chip further includes a shut-off microvalve disposed in the first delivery section, and the shut-off microvalve is used to control the on / off state of the first delivery section.

[0015] According to some embodiments of this application, the first particle is a cell, and the second particle is one of magnetic beads, cells, and microspheres.

[0016] According to some embodiments of this application, the microfluidic chip further includes: The second sample introduction module includes a third flow channel, a second waste liquid flow channel, and an enrichment flow channel. The third flow channel is connected to the second waste liquid flow channel and the enrichment flow channel, respectively. The third flow channel is used to allow a third liquid containing the first particles to pass through. The enrichment flow channel is connected to the first flow channel. The second control module includes a second waste liquid microvalve corresponding to the second waste liquid flow channel and an enrichment microvalve corresponding to the enrichment flow channel. The second waste liquid microvalve is used to control the opening and closing of the second waste liquid flow channel, and the enrichment microvalve is used to control the opening and closing of the enrichment flow channel. The third flow channel is provided with a third detection position for detecting the first particle; The microfluidic chip is configured such that: a third liquid that does not detect the first particle is discharged as waste liquid through the second waste liquid channel; a third liquid that detects the first particle flows to the enrichment channel and forms the first liquid enriched with the first particle; and the formed first liquid flows to the first channel through the enrichment channel.

[0017] According to some embodiments of this application, the diameter of the second waste liquid channel and the diameter of the enrichment channel are both larger than the diameter of the third channel.

[0018] According to some embodiments of this application, the diameter of the third flow channel is 50 μm, and the diameters of the second waste liquid flow channel and the enrichment flow channel are both 80 μm.

[0019] According to some embodiments of this application, the microfluidic chip further includes a sheath fluid channel, which is connected to the third channel, and the sheath fluid channel is used to input a sheath flow that encapsulates the third fluid into the third channel.

[0020] According to some embodiments of this application, the sheath fluid flow channel includes two second branch flow channels, which are respectively connected to the third flow channel from both sides of the third flow channel.

[0021] According to some embodiments of this application, the microfluidic chip includes a substrate layer, a control layer, and a flow channel layer stacked sequentially, wherein: The first injection module and the second injection module are disposed in the flow channel layer; The first control module and the second control module are located in the control layer.

[0022] A microfluidic system according to a second aspect of this application includes a microfluidic chip according to the first aspect of this application described above. The microfluidic system further includes a first detection module and a second detection module. The first detection module is used to detect a first particle in the first flow channel at a first detection position, and the second detection module is used to detect a second particle in the second flow channel at a second detection position.

[0023] According to some embodiments of this application, the microfluidic system further includes a sampling nozzle and a pump body. A collection hole for collecting the first liquid is provided between the enrichment channel and the first channel. The enrichment channel is connected to the first channel through the collection hole. The sampling nozzle is used to collect the first liquid in the collection hole. The pump body is used to provide a preset liquid supply pressure to pump the first liquid in the sampling nozzle into the first channel through the collection hole.

[0024] According to some embodiments of this application, the diameter of the liquid collection hole is larger than the diameter of the enrichment channel.

[0025] According to some embodiments of this application, a check valve is provided at one end of the enrichment channel near the liquid collection hole, and the check valve is used to control the opening and closing of the enrichment channel.

[0026] According to some embodiments of this application, both the first detection module and the second detection module are configured as fluorescence detection modules; or... Both the first detection module and the second detection module are configured as electrical impedance detection modules; or, Both the first detection module and the second detection module are configured as visual detection modules; or, Both the first detection module and the second detection module are configured as acoustic detection modules.

[0027] According to some embodiments of this application, the microfluidic system further includes a third detection module, which is used to detect a first particle in the third channel at the third detection location.

[0028] According to some embodiments of this application, the third detection module is configured as a fluorescence detection module; or... The third detection module is configured as an impedance detection module; or... The third detection module is configured as a visual detection module; or... The third detection module is configured as an acoustic detection module.

[0029] According to some embodiments of this application, the third detection module is configured as a fluorescence detection module, and the third flow channel is provided with a scale for indicating the third detection position.

[0030] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0031] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a pairing system according to an embodiment of this application; Figure 2 This is a schematic diagram of the state when the first particle is trapped in the first liquid outlet section in the pairing system according to an embodiment of this application; Figure 3 This is a schematic diagram of the state when the first particle and the second particle merge in a pairing system according to an embodiment of this application; Figure 4 This is a schematic diagram of the state when the first particle and the second particle pair up and form a droplet in a pairing system according to an embodiment of this application; Figure 5 This is a schematic diagram of the enrichment system and pairing system according to an embodiment of this application; Figure 6 This is a schematic diagram of the first micro-valve switching from an open state to a closed state according to an embodiment of this application; Figure 7 This is an exploded view of a microfluidic chip according to an embodiment of this application; Figure 8 The image is a bright-field image obtained by taking actual photos of the sample liquid (i.e., the third liquid) before enrichment using the enrichment system of the embodiments of this application. Figure 9 It is aimed at Figure 8 The fluorescence field image obtained by taking a real photo of the location corresponding to the bright field image shown; Figure 10 The image is a bright-field image obtained by taking actual photographs of the sample liquid (i.e., the first liquid) after enrichment by the enrichment system of the embodiments of this application. Figure 11 It is aimed at Figure 10 The fluorescence field image obtained by taking a real photo of the location corresponding to the bright field image shown; Figure 12 This is a photographic representation of the effect of droplets formed after the first and second particles are paired using the pairing system of an embodiment of this application.

[0032] Figure label: First flow channel 110, first liquid outlet section 111, second flow channel 120, second liquid outlet section 121, first inlet 122, first buffer solution flow channel 130, first conveying section 131, second inlet 132, second buffer solution flow channel 140, second conveying section 141, third inlet 142, paired flow channel 150, outlet section 151, oil flow channel 160, first branch flow channel 161, fourth inlet 162, collection flow channel 170, collection port 171, first waste liquid flow channel 180, first outlet 181; First microvalve 210, microvalve control channel 211, diaphragm 212, second microvalve 220, paired microvalve 230, first waste liquid microvalve 240, shut-off microvalve 250; Third flow channel 310, fifth inlet 311, first protrusion 312, second waste liquid flow channel 320, second outlet 321, enrichment flow channel 330, liquid collection hole 340, sheath liquid flow channel 350, second branch flow channel 351, sixth inlet 352, second protrusion 353; Second waste liquid micro valve 410, enrichment micro valve 420, check valve 430; Scale 500; Microfluidic chip 600, substrate layer 610, control layer 620, channel layer 630; First particle a, second particle b; First detection position c, second detection position d, third detection position f; Droplet e. Detailed Implementation

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0034] In the description of this application, it should be understood that if directional descriptions are involved, such as up, down, front, back, left, right, etc., indicating the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0035] In the description of this application, if words such as several, greater than, less than, exceeding, above, below, or within appear, "several" means one or more, "more than" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the number itself, and "above," "below," "within," etc. are understood to include the number itself.

[0036] In the description of this application, the use of terms such as "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0037] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0038] The microfluidic chip 600 according to an embodiment of this application includes a first sample injection module and a first control module.

[0039] Specifically, refer to Figures 1 to 5 The first injection module includes a first flow channel 110, a second flow channel 120, a first buffer solution flow channel 130, a second buffer solution flow channel 140, a paired flow channel 150, and an oil flow channel 160. The first flow channel 110, the second flow channel 120, the first buffer solution flow channel 130, and the second buffer solution flow channel 140 are all connected to the paired flow channel 150, and the paired flow channel 150 is connected to the oil flow channel 160. The first flow channel 110 is used to allow the first liquid containing the first particle a to pass through, and the second flow channel 120 is used to allow the second liquid containing the second particle b to pass through. The first control module includes a first microvalve 210 corresponding to the first flow channel 110, a second microvalve 220 corresponding to the second flow channel 120, and a paired microvalve 230 corresponding to the paired flow channel 150. The first microvalve 210 is used to control the opening and closing of the first flow channel 110, the second microvalve 220 is used to control the opening and closing of the second flow channel 120, and the paired microvalve 230 is used to control the opening and closing of the paired flow channel 150.

[0040] The first buffer channel 130 and the second buffer channel 140 are located on both sides of the paired channel 150 and are symmetrically arranged. A first delivery section 131 is provided between the end of the first buffer channel 130 and the paired channel 150, and a second delivery section 141 is provided between the end of the second buffer channel 140 and the paired channel 150. The first channel 110 has a first outlet section 111, the end of which is connected to the first delivery section 131. The second channel 120 has a second outlet section. 121, the end of the second liquid outlet section 121 is connected to the second conveying section 141. The first liquid outlet section 111 and the second liquid outlet section 121 are located on both sides of the paired flow channel 150 and are symmetrically arranged. The first liquid outlet section 111 is provided with a first detection position c for detecting the first particle a, and the second liquid outlet section 121 is provided with a second detection position d for detecting the second particle b. The distance from the first detection position c to the end of the first liquid outlet section 111 and the distance from the second detection position d to the end of the second liquid outlet section 121 are the same.

[0041] The first injection module and the first control module constitute a pairing system to pair the first particle and the second particle. During pairing, a first liquid containing the first particle a is provided through the first flow channel 110, and a second liquid containing the second particle b is provided through the second flow channel 120. When the first particle a is detected at the first detection position c, the detected first particle a is stopped at the first liquid outlet section 111. When the second particle b is detected at the second detection position d, the first particle a and the second particle b are transported to the pairing flow channel 150 to merge through the symmetrically arranged flow channel structure consisting of the first liquid outlet section 111, the first transport section 131, the first buffer flow channel 130, the second liquid outlet section 121, the second transport section 141, and the second buffer flow channel 140. Finally, droplets e are formed in the oil provided by the oil flow channel 160. The distance from the first detection position c to the end of the first outlet section 111 and the distance from the second detection position d to the end of the second outlet section 121 are the same, ensuring that the supply pressure of the first flow channel 110, the second flow channel 120, the first buffer solution flow channel 130, and the second buffer solution flow channel 140 are the same. Combined with the aforementioned symmetrical flow channel structure, this helps to shorten the time difference between the first particle a and the second particle b flowing to the pairing flow channel 150. That is, the first particle a and the second particle b can reach the pairing flow channel 150 and merge at approximately the same time, thereby improving the problem of lag in the pairing process between either the first particle a or the second particle b. This not only improves the encapsulation effect of droplet e but also helps to reduce the probability of pairing failure. Furthermore, it helps to reduce the problem of excessively large droplet e caused by excessive spacing between the first particle a and the second particle b, thus reducing the risk of droplet e breakage.

[0042] Since the response time of the control action of each microvalve is in the millisecond range, it will not affect the realization of the above-mentioned technical effects.

[0043] Specifically, the first buffer channel 130 and the second buffer channel 140 are symmetrically arranged with the center line of the paired channel 150 as the axis of symmetry, and the first outlet section 111 and the second outlet section 121 are also symmetrically arranged with the center line of the paired channel 150 as the axis of symmetry.

[0044] Reference Figure 6Taking the first microvalve 210 as an example, the first microvalve 210 includes a microvalve control channel 211 and a diaphragm 212 disposed between the microvalve control channel 211 and the first channel 110. When the first microvalve 210 is in the open state, the diaphragm 212 is in a horizontal state, allowing the first liquid to pass through the area of ​​the first channel 110 corresponding to the first microvalve 210. The diaphragm 212 can protrude into the first channel 110 under the drive of the liquid or gas in the microvalve control channel 211. When the diaphragm 212 is close to the inner wall of the first channel 110, the first microvalve 210 is in the closed state, at which time the first liquid cannot pass through the area of ​​the first channel 110 corresponding to the first microvalve 210. Specifically, the inner wall of the diaphragm 212 corresponding to the first microvalve 210 in the first channel 110 is arc-shaped to facilitate fitting the diaphragm 212 of the first microvalve 210, thereby ensuring the shut-off effect.

[0045] The other microvalves mentioned above and the other microvalves described below can be understood with reference to the specific structure of the first microvalves 210.

[0046] Reference Figures 2 to 5 In some embodiments, the end of the paired flow channel 150 has an outlet section 151, the cross-sectional area of ​​which decreases along its own liquid outflow direction. This helps to reduce the distance between the first particle a and the second particle b in the generated droplet e, thereby further reducing the volume of the generated droplet e. Based on this, uniform and stable small droplets containing the first particle a and the second particle b can be effectively generated, while preventing the droplets from being stretched too long and breaking.

[0047] It should be noted that the "cross-sectional area of ​​the outlet section 151" mentioned above only corresponds to the flow channel portion and does not involve the physical portion that encloses and forms the flow channel.

[0048] Specifically, the longitudinal section of exit section 151 is an isosceles trapezoid.

[0049] It should be noted that the "longitudinal section of the outlet section 151" mentioned above only corresponds to the flow channel portion and does not involve the physical portion that encloses and forms the flow channel.

[0050] In some of these embodiments, the diameter of the end outlet of the outlet section 151 is 20 μm to 40 μm, which is beneficial for generating small and stable droplets e.

[0051] Reference Figures 1 to 5 In some embodiments, the oil flow channel 160 includes two symmetrically arranged first branch channels 161, the ends of which are connected to the ends of the paired channel 150 from both sides, so that the oil provided by the oil flow channel 160 can better exert a shearing effect and generate droplets e containing the first particle a and the second particle b.

[0052] Reference Figures 1 to 5 In some embodiments, the pairing system further includes a collection channel 170 connected to the end of the pairing channel 150, the centerline of the collection channel 170 being collinear with the centerline of the pairing channel 150, so that the generated droplets e can be collected more smoothly.

[0053] Reference Figures 1 to 5 In some embodiments, the pairing system further includes a first waste liquid flow channel 180 and a first waste liquid microvalve 240 corresponding to the first waste liquid flow channel 180. The first waste liquid flow channel 180 is connected to the end of the pairing flow channel 150 away from the oil flow channel 160. The first waste liquid microvalve 240 is used to control the opening and closing of the first waste liquid flow channel 180. Specifically, when the pairing microvalve 230 is in the closed state and the first microvalve 210 and the first waste liquid microvalve 240 are in the open state, the liquid in the first flow channel 110 can flow out through the first waste liquid flow channel 180; when the pairing microvalve 230 is in the closed state and the second microvalve 220 and the first waste liquid microvalve 240 are in the open state, the liquid in the second flow channel 120 can flow out through the first waste liquid flow channel 180.

[0054] It should be noted that the first particle a and the second particle b will gradually approach and reach the pairing flow channel 150 as they follow the flow of the first liquid and the second liquid, respectively. When the first particle a and the second particle b have not yet reached the pairing flow channel 150, the first liquid and the second liquid will be continuously discharged as waste liquid through the first waste liquid micro valve 240.

[0055] Reference Figures 1 to 5 In some embodiments, the pairing system further includes a shut-off microvalve 250, which is disposed in the first conveying section 131 and is used to control the opening and closing of the first conveying section 131. By setting the shut-off microvalve 250, the first particle a can be prevented from being carried by the second liquid into the first waste liquid channel 180, resulting in the encapsulated droplet e containing only the second particle b, thereby ensuring the encapsulation success rate. By controlling the opening and closing of the shut-off microvalve 250, the first particle a can be prevented from being lost through the first waste liquid channel 180 during the waiting process for pairing, without affecting the pairing and encapsulation of the first particle a and the second particle b.

[0056] It should be noted that before the shut-off microvalve 250 switches to the closed state, the second microvalve 220 can remain open, allowing the second liquid to continuously discharge from the first waste liquid channel 180 without capturing the second particle b. Alternatively, the second microvalve 220 can remain closed initially, and then be opened after the shut-off microvalve 250 switches to the closed state to capture the individual second particle b.

[0057] Specifically, refer to Figures 2 to 4 When the first particle a is detected at the first detection position c, the first micro valve 210 and the shut-off micro valve 250 are closed to stop the first particle a at the first liquid outlet section 111, and at the same time, the subsequent first particle a is restricted from entering the first liquid outlet section 111. When the second particle b is detected at the second detection position d, the second micro valve 220 is closed to restrict the subsequent second particle b from entering the second liquid outlet section 121. At the same time, the shut-off micro valve 250 and the paired micro valve 230 are opened and the first waste liquid micro valve 240 is closed, so that the first particle a and the second particle b enter the paired flow channel 150 and merge. The merged first particle a and the second particle b eventually form droplets e in the oil provided by the oil flow channel 160.

[0058] In some of these embodiments, the first particle a is a cell, and the second particle b is one of magnetic beads, cells, or microspheres.

[0059] Specifically, the microspheres can be one of polyethylene microspheres, magnetic microspheres, or fluorescent magnetic microspheres.

[0060] In some embodiments, the microfluidic chip 600 further includes a second sample introduction module and a second control module.

[0061] Specifically, refer to Figure 5 The second injection module includes a third flow channel 310, a second waste liquid flow channel 320, and an enrichment flow channel 330. The third flow channel 310 is connected to the second waste liquid flow channel 320 and the enrichment flow channel 330, respectively. The third flow channel 310 is used to allow the third liquid containing the first particle a to pass through. The enrichment flow channel 330 is connected to the first flow channel 110. The second control module includes a second waste liquid microvalve 410 corresponding to the second waste liquid flow channel 320 and an enrichment microvalve 420 corresponding to the enrichment flow channel 330. The second waste liquid microvalve 410 is used to control the opening and closing of the second waste liquid flow channel 320, and the enrichment microvalve 420 is used to control the opening and closing of the enrichment flow channel 330.

[0062] The third flow channel 310 is provided with a third detection position f for detecting the first particle a.

[0063] The microfluidic chip 600 is configured such that: the third liquid that does not detect the first particle a is discharged as waste liquid through the second waste liquid channel 320; the third liquid that detects the first particle a flows to the enrichment channel 330 and forms a first liquid enriched with the first particle a; and the formed first liquid flows to the first channel 110 through the enrichment channel 330.

[0064] The second sample injection module and the second control module constitute an enrichment system. When the first particle is a rare cell, the enrichment system can be used to increase the enrichment level of the first particle a in the sample solution, thereby forming a first liquid with a high content of the first particle a. This can improve the speed at which the pairing system screens the first particle a, thus improving the pairing efficiency of the first particle a and the second particle b. Specifically, during the process of providing the third liquid containing the first particle a through the third flow channel 310, when the first particle a is detected at the third detection position f, the enrichment microvalve 420 is opened and the second waste liquid microvalve 410 is closed, so that the sample solution containing the first particle a flows to the enrichment flow channel 330 and forms a first liquid enriched with the first particle a leading to the first flow channel 110. When the first particle a is not detected at the third detection position f, the second waste liquid microvalve 410 is opened and the enrichment microvalve 420 is closed, so that the sample solution without the first particle a flows as waste liquid to the second waste liquid flow channel 320 and is finally discharged.

[0065] It should be noted that rare cells refer to cells that appear in small numbers in solid tissues or liquid biopsy samples, while other cell types surrounding them are very abundant. For example, circulating tumor cells (CTCs) are very rare in circulating blood, which is rich in cells. Specifically, only 1 to 10 CTCs can be detected in one milliliter of whole blood, while the same volume of blood contains millions of white blood cells and hundreds of millions of red blood cells.

[0066] In some embodiments, the diameters of the second waste liquid channel 320 and the enrichment channel 330 are both larger than the diameter of the third channel 310, which helps to prevent particles in the sample liquid from clogging the junction of the third channel 310 and the second waste liquid channel 320, as well as the junction of the third channel 310 and the enrichment channel 330.

[0067] In some of these embodiments, the diameter of the third flow channel 310 is 50 μm, and the diameters of the second waste liquid flow channel 320 and the enrichment flow channel 330 are both 80 μm.

[0068] Reference Figure 5 In some embodiments, the enrichment system further includes a sheath fluid channel 350, which is connected to a third channel 310. The sheath fluid channel 350 is used to input a sheath fluid encapsulating a third liquid into the third channel 310. By setting the sheath fluid to constrain the third liquid, the third liquid can be made to flow in the central region of the channel, preventing the first particle a in the third liquid from getting too close to the inner wall of the channel.

[0069] Reference Figure 5 In some embodiments, the sheath fluid flow channel 350 includes two second branch flow channels 351, which are connected to the third flow channel 310 from both sides, thereby enabling the third fluid to be confined between the two sheath flows.

[0070] Reference Figure 7 In some embodiments, the microfluidic chip 600 includes a base layer 610, a control layer 620, and a channel layer 630 stacked sequentially, wherein: The first and second injection modules are located in the flow channel layer 630; The first control module and the second control module are located in the control layer 620.

[0071] The microfluidic system according to an embodiment of this application includes the microfluidic chip 600 described above. The microfluidic system also includes a first detection module and a second detection module. The first detection module is used to detect a first particle a in a first flow channel 110 at a first detection position c, and the second detection module is used to detect a second particle b in a second flow channel 120 at a second detection position d.

[0072] In some embodiments, the microfluidic system further includes a dispensing nozzle and a pump body, see reference Figure 5 A collection hole 340 for collecting the first liquid is provided between the enrichment channel 330 and the first channel 110. The enrichment channel 330 is connected to the first channel 110 through the collection hole 340. The sampling nozzle is used to collect the first liquid in the collection hole 340, and the pump body is used to provide a preset liquid supply pressure to pump the first liquid in the sampling nozzle into the first channel 110 through the collection hole 340. In use, the first liquid in the collection hole 340 is collected by the sampling nozzle, and then the first liquid in the sampling nozzle is pumped into the first channel 110 through the collection hole 340 by the pump body providing a preset liquid supply pressure. The preset liquid supply pressure provided by the pump body helps to prevent the first particle a from adhering to the inner wall of the channel, thereby reducing the loss of the first particle a and improving the recovery rate of the first particle a.

[0073] Reference Figure 5 In some embodiments, the diameter of the collection hole 340 is larger than the diameter of the enrichment channel 330, so that more first liquid can be collected in the collection hole 340, thereby enabling the spotting nozzle to quickly collect enough first liquid, which in turn helps to improve the efficiency of the first liquid being transferred from the enrichment channel 330 to the first channel 110.

[0074] Reference Figure 5In some embodiments, a check valve 430 is provided at one end of the enrichment channel 330 near the collection hole 340. The check valve 430 is used to control the opening and closing of the enrichment channel 330. When the first liquid in the sampling nozzle is pumped into the first channel 110 through the collection hole 340 by the pump body, the check valve 430 is closed, which can prevent the first liquid from flowing to the enrichment channel 330 through the collection hole 340, thereby helping to further improve the efficiency of the first liquid being transferred from the enrichment channel 330 to the first channel 110.

[0075] Specifically, the microfluidic system also includes a controller, wherein: In some embodiments, both the first detection module and the second detection module are configured as fluorescence detection modules. Specifically, the first detection module includes a light source and a light detection device. The controller is configured to control the light source to emit a light beam towards the first liquid outlet section 111. When the first particle a is irradiated by the light source, it can be excited to fluoresce. When the light detection device detects the fluorescence, the first detection module detects the first particle a. As an example, the light source is a laser, and the light detection device is a photomultiplier tube. When the fluorescence emitted by a single first particle a is received, the photomultiplier tube can convert the light signal into an electrical signal and transmit it to the controller. The specific structure and working principle of the second detection module can be understood by referring to the first detection module. At this time, the first detection position c is the position of the light beam emitted by the first detection module, and the second detection position d is the position of the light beam emitted by the second detection module.

[0076] It should be noted that in some other embodiments, both the first detection module and the second detection module are configured as impedance detection modules. Specifically, the first detection module includes a detection electrode that extends into the first liquid outlet section 111, and the controller is configured to detect the first particle a based on the signal from the detection electrode. The specific structure and working principle of the second detection module can be understood by referring to the first detection module. In this case, the first detection position c is the position of the detection electrode of the first detection module, and the second detection position d is the position of the detection electrode of the second detection module.

[0077] It should be noted that in some other embodiments, both the first detection module and the second detection module are configured as visual detection modules. Specifically, the first detection module includes a camera, and the controller is configured to control the camera to capture images of the first liquid outlet section 111, and the controller detects the first particle a based on the images of the first liquid outlet section 111. The specific structure and working principle of the second detection module can be understood by referring to the first detection module. In this case, the first detection position c is the position of the camera of the first detection module, and the second detection position d is the position of the camera of the second detection module.

[0078] It should be noted that in some other embodiments, both the first detection module and the second detection module are configured as acoustic detection modules. The principle of the acoustic detection method is well-known in the art and will not be elaborated upon here.

[0079] In some embodiments, the microfluidic system further includes a third detection module for detecting a first particle a within the third flow channel 310 at a third detection position f.

[0080] In some embodiments, the third detection module is configured as a fluorescence detection module. The specific structure and working principle of the third detection module can be understood by referring to the first detection module.

[0081] It should be noted that in some other embodiments, the third detection module is configured as an impedance detection module. The specific structure and working principle of the third detection module can be understood by referring to the first detection module.

[0082] It should be noted that in some other embodiments, the third detection module is configured as a visual detection module. The specific structure and working principle of the third detection module can be understood by referring to the first detection module.

[0083] It should be noted that in some other embodiments, the third detection module is configured as an acoustic detection module.

[0084] Reference Figure 5 In some embodiments, when the third detection module is configured as a fluorescence detection module, a scale 500 is provided at the third flow channel 310 to indicate the third detection position f, so that the position of the beam emitted by the third detection module can be found quickly and accurately during the experiment, thereby improving the experimental efficiency.

[0085] Reference Figure 1 and Figure 5 In some embodiments, the second flow channel 120 has a first inlet 122 for inputting a second liquid containing the second particle b, the first buffer flow channel 130 has a second inlet 132 for inputting a buffer solution, the second buffer flow channel 140 has a third inlet 142 for inputting a buffer solution, the oil flow channel 160 has a fourth inlet 162 for inputting oil, the collection flow channel 170 has a collection port 171 for outputting droplets, the first waste liquid flow channel 180 has a first outlet 181 for discharging waste liquid, the third flow channel 310 has a fifth inlet 311 for inputting a third liquid containing the first particle a, the second waste liquid flow channel 320 has a second outlet 321 for discharging waste liquid, and the sheath fluid flow channel 350 has a sixth inlet 352 for inputting sheath fluid.

[0086] The fifth inlet 311 has multiple spaced-apart columnar first protrusions 312. The gap between two adjacent first protrusions 312 allows a third liquid containing first particles a to pass through and is used to filter impurities in the third liquid. The gap between two adjacent first protrusions 312 can be adjusted according to actual needs. The sixth inlet 352 has multiple spaced-apart columnar second protrusions 353. The gap between two adjacent second protrusions 353 allows sheath fluid to pass through and is used to filter impurities in the sheath fluid. The gap between two adjacent second protrusions 353 can be adjusted according to actual needs.

[0087] Specifically, the working process of the microfluidic system according to the embodiments of this application is as follows: A third liquid containing the first particle a is provided through the third flow channel 310. The first particle a in the third liquid in the third flow channel 310 is detected by the third detection module at the third detection position f. When the first particle a is not detected, the sample liquid without the first particle a is driven to flow as waste liquid to the second waste liquid flow channel 320 and finally discharged. When the first particle a is detected, the sample liquid containing the first particle a is driven to flow to the enrichment flow channel 330 to form a first liquid enriched with the first particle a leading to the first flow channel 110. The first liquid enriched with the first particle a is provided through the first flow channel 110. The first particle a in the first liquid in the first flow channel 110 is detected by the first detection module at the first detection position c. When the first particle a is not detected, the sample liquid without the first particle a is driven to flow as waste liquid to the first waste liquid flow channel 180 and finally discharged. When the first particle a is detected, the first liquid is stopped so that the first particle a is stopped at the first liquid outlet section 111. When the detected first particle a is intercepted at the first outlet section 111, a second liquid containing the second particle b is provided through the second flow channel 120. At the second detection position d, the second detection module detects the second particle b in the second liquid within the second flow channel 120. When the second particle b is not detected, the sample liquid without the second particle b is driven as waste liquid to the first waste liquid flow channel 180 and finally discharged. When the second particle b is detected, the first particle a and the second particle b are driven into the pairing flow channel 150 to merge through the buffer solution. The merged first particle a and the second particle b form droplets e through the outlet section 151 of the pairing flow channel 150 and are encapsulated by the oil provided by the oil flow channel 160. Finally, they are collected through the collection flow channel 170.

[0088] Specifically, when using the aforementioned enrichment system to enrich and sort the sample solution, the flow rate and concentration of the sample solution were controlled to achieve a throughput of 10,000 particles / s (i.e., 10,000 particles per second). Five sets of experiments were conducted, and the initial positive rate (before enrichment) and the final positive rate (after enrichment) of the sample solution are shown in the table below:

[0089] As shown in the table above, after enriching and sorting the sample solution using the aforementioned enrichment system, the final positive rate of the sample solution can be increased to more than 100 times the initial positive rate. The positive rate is the proportion of positive particles (i.e., target particles) in the sample solution out of all particles in the sample solution.

[0090] See Figure 8 and Figure 9 ,in, Figure 8 The image is a bright-field image obtained by taking actual photos of the sample solution (i.e., the third liquid) before enrichment using the aforementioned enrichment system. Figure 9 It is aimed at Figure 8 The fluorescence field image obtained by photographing the location corresponding to the bright field image shown (the particles with green fluorescence in the image are the target particles) is obtained from... Figure 8 and Figure 9 It can be seen that the sample solution before enrichment by the above-mentioned enrichment system contains a large number of particles other than the target particle (i.e., the first particle a), and the positive rate of the target particle (corresponding to the initial positive rate) is low.

[0091] See Figure 10 and Figure 11 ,in, Figure 10 The image is a bright-field image obtained by taking actual photographs of the sample solution (i.e., the first liquid) after enrichment using the aforementioned enrichment system. Figure 11 It is aimed at Figure 10 The fluorescence field image obtained by photographing the location corresponding to the bright field image shown (the particles with green fluorescence in the image are the target particles) is obtained from... Figure 10 and Figure 11 It can be seen that, compared to Figure 8 and Figure 9 As shown, in the sample solution enriched by the above-mentioned enrichment system, the number of particles other than the target particles is significantly reduced, and the positive rate of the target particles (corresponding to the final positive rate) is significantly increased.

[0092] Specifically, through experimental verification, when the above-mentioned pairing system is used to pair the first particle a and the second particle b, the pairing success rate can reach over 98%.

[0093] It should be noted that, Figures 8 to 11 The images were taken by a fully automated cell analyzer (such as the Countstar Altair fully automated cell analyzer). Figures 8 to 11 The line segments marked "100μm" represent the scale, meaning that the length of the line segments marked "100μm" in the figure is 100μm.

[0094] See Figure 12 ,in, Figure 12 This is a photographic representation of the droplet e formed after the first particle a and the second particle b are paired using the aforementioned pairing system. Figure 12 It can be seen that the first particle a and the second particle b, after being paired through the above pairing system, have a high pairing success rate.

[0095] It should be noted that, Figure 12 It was taken with a microscope (such as a Zeiss microscope).

[0096] In the description of this specification, the use of terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A microfluidic chip, characterized in that, include: The first injection module includes a first flow channel, a second flow channel, a first buffer flow channel, a second buffer flow channel, a paired flow channel, and an oil flow channel. The first flow channel, the second flow channel, the first buffer flow channel, and the second buffer flow channel are all connected to the paired flow channel. The paired flow channel is connected to the oil flow channel. The first flow channel is used to allow a first liquid containing a first particle to pass through, and the second flow channel is used to allow a second liquid containing a second particle to pass through. The first control module includes a first micro valve corresponding to the first flow channel, a second micro valve corresponding to the second flow channel, and a paired micro valve corresponding to the paired flow channel. The first micro valve is used to control the opening and closing of the first flow channel, the second micro valve is used to control the opening and closing of the second flow channel, and the paired micro valve is used to control the opening and closing of the paired flow channel. The first buffer channel and the second buffer channel are located on both sides of the paired channel and are symmetrically arranged. A first delivery section is provided between the end of the first buffer channel and the paired channel, and a second delivery section is provided between the end of the second buffer channel and the paired channel. The first channel has a first outlet section, the end of which is connected to the first delivery section. The second channel has a second outlet section, the end of which is connected to the second delivery section. The first outlet section and the second outlet section are located on both sides of the paired channel and are symmetrically arranged. The first outlet section has a first detection position for detecting a first particle, and the second outlet section has a second detection position for detecting a second particle. The distance from the first detection position to the end of the first outlet section and the distance from the second detection position to the end of the second outlet section are the same.

2. The microfluidic chip as described in claim 1, characterized in that, The end of the paired flow channel has an outlet section, the cross-sectional area of ​​which decreases along its own liquid outflow direction.

3. The microfluidic chip as described in claim 2, characterized in that, The diameter of the outlet at the end of the outlet section is 20μm to 40μm.

4. The microfluidic chip as described in claim 1, characterized in that, The oil flow channel includes two symmetrically arranged first branch flow channels, and the ends of the two first branch flow channels are respectively connected to the ends of the paired flow channels from both sides.

5. The microfluidic chip as described in claim 1, characterized in that, The microfluidic chip also includes a collection channel, which is connected to the end of the paired channel, and the centerline of the collection channel is collinear with the centerline of the paired channel.

6. The microfluidic chip as described in claim 1, characterized in that, The microfluidic chip further includes a first waste liquid channel and a first waste liquid microvalve corresponding to the first waste liquid channel. The first waste liquid channel is connected to the end of the paired channel away from the oil channel. The first waste liquid microvalve is used to control the opening and closing of the first waste liquid channel.

7. The microfluidic chip as described in claim 6, characterized in that, The microfluidic chip also includes a shut-off microvalve, which is disposed in the first delivery section and is used to control the on / off state of the first delivery section.

8. The microfluidic chip as described in claim 1, characterized in that, The first particle is a cell, and the second particle is one of magnetic beads, cells, or microspheres.

9. The microfluidic chip according to any one of claims 1 to 8, characterized in that, The microfluidic chip also includes: The second sample introduction module includes a third flow channel, a second waste liquid flow channel, and an enrichment flow channel. The third flow channel is connected to the second waste liquid flow channel and the enrichment flow channel, respectively. The third flow channel is used to allow a third liquid containing the first particles to pass through. The enrichment flow channel is connected to the first flow channel. The second control module includes a second waste liquid microvalve corresponding to the second waste liquid flow channel and an enrichment microvalve corresponding to the enrichment flow channel. The second waste liquid microvalve is used to control the opening and closing of the second waste liquid flow channel, and the enrichment microvalve is used to control the opening and closing of the enrichment flow channel. The third flow channel is provided with a third detection position for detecting the first particle; The microfluidic chip is configured such that: a third liquid that does not detect the first particle is discharged as waste liquid through the second waste liquid channel; a third liquid that detects the first particle flows to the enrichment channel and forms the first liquid enriched with the first particle; and the formed first liquid flows to the first channel through the enrichment channel.

10. The microfluidic chip as described in claim 9, characterized in that, The diameters of the second waste liquid flow channel and the enrichment flow channel are both larger than the diameter of the third flow channel.

11. The microfluidic chip as described in claim 10, characterized in that, The diameter of the third flow channel is 50 μm, and the diameters of the second waste liquid flow channel and the enrichment flow channel are both 80 μm.

12. The microfluidic chip as described in claim 9, characterized in that, The microfluidic chip also includes a sheath fluid channel, which is connected to the third channel and is used to input a sheath fluid encapsulating the third fluid into the third channel.

13. The microfluidic chip as described in claim 12, characterized in that, The sheath fluid flow channel includes two second branch flow channels, which are respectively connected to the third flow channel from both sides.

14. The microfluidic chip as described in claim 9, characterized in that, The microfluidic chip comprises a substrate layer, a control layer, and a flow channel layer stacked sequentially, wherein: The first injection module and the second injection module are disposed in the flow channel layer; The first control module and the second control module are located in the control layer.

15. A microfluidic system, characterized in that, The microfluidic system includes the microfluidic chip as described in any one of claims 9 to 14, and further includes a first detection module and a second detection module, wherein the first detection module is used to detect a first particle in the first flow channel at the first detection position, and the second detection module is used to detect a second particle in the second flow channel at the second detection position.

16. The microfluidic system as described in claim 15, characterized in that, The microfluidic system further includes a sampling nozzle and a pump body. A collection hole for collecting the first liquid is provided between the enrichment channel and the first channel. The enrichment channel is connected to the first channel through the collection hole. The sampling nozzle is used to collect the first liquid in the collection hole. The pump body is used to provide a preset liquid supply pressure to pump the first liquid in the sampling nozzle into the first channel through the collection hole.

17. The microfluidic system as described in claim 16, characterized in that, The diameter of the liquid collection hole is larger than the diameter of the enrichment channel.

18. The microfluidic system as described in claim 16, characterized in that, A check valve is provided at one end of the enrichment channel near the collection hole, and the check valve is used to control the opening and closing of the enrichment channel.

19. The microfluidic system as described in claim 15, characterized in that, Both the first detection module and the second detection module are configured as fluorescence detection modules; or, Both the first detection module and the second detection module are configured as electrical impedance detection modules; or, Both the first detection module and the second detection module are configured as visual detection modules; or, Both the first detection module and the second detection module are configured as acoustic detection modules.

20. The microfluidic system as described in claim 15, characterized in that, The microfluidic system further includes a third detection module, which is used to detect the first particle in the third channel at the third detection location.

21. The microfluidic system as described in claim 20, characterized in that, The third detection module is configured as a fluorescence detection module; or... The third detection module is configured as an impedance detection module; or... The third detection module is configured as a visual detection module; or... The third detection module is configured as an acoustic detection module.

22. The microfluidic system as described in claim 21, characterized in that, The third detection module is configured as a fluorescence detection module, and the third flow channel is provided with a scale for indicating the third detection position.

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