A microfluidic chip

Abstract

The present invention provides a microfluidic chip, belonging to the field of microfluidic technology, including: a positioning hole, the positioning hole is used to connect with a detection instrument; a multi-connected injection port, the multi-connected injection port is at least one; a distribution pool, the distribution pool is connected to one of the multi-connected injection ports; a receiving chamber, the receiving chamber includes a plurality of chambers, which are respectively connected to the distribution pool; the receiving chamber is close to the rotation center, and a microfluidic valve is arranged at a position connected to the flow channel; the positioning hole, the multi-connected injection port, the distribution pool and the receiving chamber are arranged away from the rotation center in sequence. By designing the structure of the microfluidic chip, cross contamination between different reaction pools is avoided, and each chamber is connected by a low-resistance fluid pipeline, which reduces the speed required for centrifugation, reduces the difficulty of instrument development and increases the life of the instrument, and only one centrifugation operation is required to realize the transfer and distribution of liquids and realize the sealing of the reaction pool, simplifying the operation process.

Description

Technical Field

[0001] The present application relates to the field of microfluidics technology, and in particular to a microfluidics chip. Background Art

[0002] Microfluidic chips are a microtechnology platform technology that integrates basic operating units such as sample preparation, reaction, separation and detection involved in various chemical, biological and medical analysis fields into a chip with a micron-level channel structure of several square centimeters. It uses controllable fluids to complete various functions of conventional chemical and biomedical laboratories. Due to its miniaturization, integration, high throughput, low energy consumption, and rapid analysis, it has been widely used in biology, medicine, environmental protection, food safety and new drug research. Centrifugal microfluidic chips are an important branch of the microfluidics field. Since they only need one motor to provide centrifugal force for liquid manipulation, the supporting equipment of centrifugal microfluidic chips is very simple and economical. At the same time, it can better meet the needs of point-of-care diagnosis (POCT) for miniaturization of instruments, making centrifugal microfluidic chips increasingly used in the field of point-of-care diagnosis.

[0003] At present, microfluidic chips are mainly used for testing single samples, which cannot meet the needs of high-throughput testing of the above diseases. At the same time, in the process of simultaneous testing of multiple indicators, the problem of cross-contamination between reaction pools has received more and more attention. As a detection tool, whether the microcontroller chip can be conveniently connected with conventional molecular biology operation steps is also a very important part of whether the product can be put into practice. Summary of the invention

[0004] The purpose of the present invention is to provide a microfluidic chip. By designing the structure of the microfluidic chip, cross contamination between different reaction pools is avoided, and each chamber is connected by a low-resistance fluid pipeline, which reduces the speed required for centrifugation, reduces the difficulty of instrument development and increases the life of the instrument, and only requires one centrifugation operation to achieve liquid transfer, distribution and reaction pool sealing, simplifying the operation process.

[0005] The present invention adopts the following technical scheme.

[0006] A microfluidic chip comprises: a positioning hole, the positioning hole is used to connect with a detection instrument; a multi-connected injection port, the multi-connected injection port is at least one; a distribution pool, the distribution pool is connected to one of the multi-connected injection ports; a accommodating chamber, the accommodating chamber comprises a plurality of chambers, each of which is connected to the distribution pool; a microfluidic valve is arranged at a position of the accommodating chamber close to a rotation center and connected to a flow channel; the positioning hole, the multi-connected injection port, the distribution pool and the accommodating chamber are arranged in sequence away from the rotation center.

[0007] Furthermore, the connection between the multi-injection port and the distribution pool is located at the circumferential end of the distribution pool around the rotation center, and the angle between the bottom surface of the distribution pool and the rotation center radially away from the connection is not greater than 90°.

[0008] Furthermore, the microfluidic valve includes: a valve seat, which is located at the connection between the flow channel and the containing chamber, and the flow channel, the valve seat and the containing chamber are successively away from the rotation center, and the valve seat has a sealing surface; a valve core, the density of the valve core is less than the density of the sample liquid, and the valve core has a spherical outer surface, and the spherical outer surface cooperates with the sealing surface to achieve sealing of the containing chamber.

[0009] Furthermore, the valve core is made of hollow or foamed flexible material.

[0010] Furthermore, the diameter of the valve core does not exceed 2 mm.

[0011] Furthermore, the sealing surface is a trapezoidal cylindrical surface, the small end of the trapezoidal cylindrical surface is connected to the flow channel, the angle between the two hypotenuses of the trapezoidal cylindrical surface is 1-3°, and the large end of the trapezoidal cylindrical surface is connected to the accommodating chamber; the ratio of the diameter of the small end of the trapezoidal cylindrical surface to the valve core diameter is in the range of 0.8-0.9, and the height of the trapezoidal cylindrical surface is 2-4mm.

[0012] Furthermore, a compressible elastic component is provided in the accommodating chamber, and the elastic component is located in the accommodating chamber at a position away from the rotation center relative to the valve seat.

[0013] Furthermore, the elastic component has an elastic membrane and an outer wall, the elastic membrane and the outer wall form a sealed cavity, the elastic membrane is located inside the accommodating cavity, and the outer wall is fixedly connected to the accommodating cavity wall.

[0014] Furthermore, the sealing cavity is filled with a compound, the outer wall has a fixed portion connected to the elastic membrane, the non-fixed portion in the middle of the fixed portion area bulges outward to form a pressing portion, and a puncture needle is provided on the pressing portion close to the sealing cavity side, and the puncture needle punctures the elastic membrane by pressing the pressing portion.

[0015] Furthermore, a stopper is provided on the sealing surface of the valve seat; when the elastic membrane changes from an extruded state to an extended state, the valve core at a position farther from the rotation center passes over the stopper to reach a position closer to the rotation center.

[0016] Furthermore, the sealing surface is a trapezoidal cylindrical surface, the small end of the trapezoidal cylindrical surface is connected to the flow channel, and the large end of the trapezoidal cylindrical surface is connected to the accommodating chamber; the stopper is annular, and the annular plane is perpendicular to the axis of the trapezoidal cylindrical surface.

[0017] Furthermore, the cross-sectional shape of the annular stop portion is a triangle, wherein the triangle faces the direction of the rotation center, with the trapezoidal cylindrical surface as the base, and the height of the triangle is 1 / 10-1 / 5 of the diameter of the circle formed by the line connecting the plane formed by the vertices of the annular stop portion and the intersection of the trapezoidal cylindrical surface; the diameter of the circle formed by the line connecting the plane formed by the vertices of the annular stop portion and the trapezoidal cylindrical surface is not greater than the diameter of the valve core.

[0018] The present invention provides a microfluidic chip, which has the following beneficial technical effects compared with the prior art:

[0019] (1) The microfluidic chip provided by the present invention can be adapted to a multi-row pipette, such as the eight-row pipette given in the embodiment of the present application. By adjusting the chip design, the detection requirements of different sample throughputs can be met, and each sample can achieve joint detection of multiple targets. In addition, by adding a microfluidic valve in the containing chamber, cross-contamination caused by fluid crosstalk between the reaction pools can be effectively avoided. At the same time, the connection between the distribution pool and the reaction pool is achieved through a low-resistance fluid pipeline with a small flow resistance, which can greatly reduce the centrifugal speed required for the liquid to enter the reaction pool, reduce the difficulty of developing the detection instrument, and at the same time increase the service life of the instrument, and only one centrifugation operation is required.

[0020] (2) To achieve simultaneous detection of multiple samples and avoid repeated sample loading, the chip sample loading hole design of the present invention is compatible with a standard eight-row pipette, and samples can be directly loaded through a pipette, which greatly reduces the labor intensity of operators and reduces the probability of errors.

[0021] (3) The present invention proposes several different sample loading port structures, including those along the radial direction and those in a center position matrix. The purpose of the design is to arrange the sample loading ports reasonably to achieve chip miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A structural diagram of a microfluidic chip provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of a microfluidic valve provided in an embodiment of the present invention;

[0025] Figure 3 for Figure 2 A partial enlarged view of point E in the middle;

[0026] Figure 4 A schematic diagram of the installation position of the elastic component provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the structure of an elastic component provided by an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of another elastic component structure provided by an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of a needle structure of another elastic component provided by an embodiment of the present invention;

[0030] Figure 8 A schematic diagram of a valve seat structure with a stopper provided in an embodiment of the present invention;

[0031] Fig. 9 A schematic diagram of the structure of a stopper provided in an embodiment of the present invention;

[0032] Fig.10 A schematic diagram of the structure of a second microfluidic chip provided in an embodiment of the present invention;

[0033] Fig.11 A schematic diagram of the structure of a third microfluidic chip provided in an embodiment of the present invention;

[0034] Fig.12 A schematic diagram of the structure of a fourth microfluidic chip provided in an embodiment of the present invention.

[0035] Figure numerals: 1. valve seat; 10. trapezoidal cylindrical surface; 11. small end; 12. large end; 13. stopper; 2. valve core; 3. elastic component; 30. elastic membrane; 31. outer wall; 310. fixing part; 311. pressing part; 312. puncture needle; 3120. connecting part; 3121. needle; 32. sealing cavity; 33. compound; 01. flow channel; 02. containing chamber; 020. containing chamber wall; 4. chip body; 40. positioning hole; 41. multi-injection port; 42. distribution pool. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The embodiment of the present invention discloses a microfluidic chip, such as Figure 1 As shown, it includes: a positioning hole 40, the positioning hole 40 is used to connect with the detection instrument; a multi-connected injection port 41, the multi-connected injection port 41 is at least one, Figure 1 There are two multi-injection ports, each of which has 8 sample addition ports; a distribution pool 42, which is connected to one of the multi-injection ports 41; a accommodating chamber 02, which acts as a reaction pool in this embodiment, and includes a plurality of accommodating chambers, which are respectively connected to the distribution pools 42; a microfluidic valve is provided at a position of the accommodating chamber 02 close to the rotation center and connected to the flow channel; the positioning hole 40, the multi-injection port 41, the distribution pool 42 and the accommodating chamber 02 are sequentially arranged away from the rotation center.

[0042] During the chip preparation process, freeze-dried microspheres of the amplification reaction system are added to each injection well in addition to the primer sequence, and can be evenly mixed with the sample during the sample addition process; at the same time, the primer sequence of the target to be detected is added to each reaction pool respectively, and the reaction pools with the same serial number in each group have the same sequence added to facilitate amplification detection of multiple samples.

[0043] like Figure 1 As shown in the figure, this design includes two groups of eight-connected injection holes. The liquid enters from one side of the distribution pool and is filled in sequence. It is suitable for the detection of 6 indicators. The text only describes one group. The operation, fluid movement process and reaction process of the other groups of injection holes are the same.

[0044] Use an eight-row pipette to add 8 different samples to be tested with extracted nucleic acid to the eight-row injection holes at the same time, repeatedly blow and beat to dissolve the freeze-dried microspheres in the samples, and make the samples pass through the sample pool of the multi-row injection port 41 and the low-resistance fluid pipeline into the distribution pool 42, and then make the samples flow into the receiving chamber 02 in sequence through the low-resistance fluid pipeline at a centrifugal speed of 1000rpm. The microfluidic valve allows the sample to enter the receiving chamber 02. When the receiving chamber 02 is full, the receiving chamber 02 is closed. The sample entering the receiving chamber 02 dissolves the freeze-dried primer stored therein, and performs an amplification reaction under the conditions set by the detection instrument. After 20 minutes, the reaction ends, and the fluorescence in each reaction pool is detected by the fluorescence recognition device in the instrument, and the results of the designed 6 indicators in the sample to be tested can be measured, so as to achieve the joint detection of 6 indicators in 16 samples.

[0045] like Figure 1 As shown, the connection between the multi-injection port 41 and the distribution pool 42 is located at the circumferential end of the distribution pool 42 around the rotation center, and the angle a0 between the bottom surface of the distribution pool 42 and the rotation center radial R away from the connection is not greater than 90°. L is the tangent of the intersection of the rotation center radial R and the bottom surface of the distribution pool 42, and the angle a0 between the two is not greater than 90°. The sample flows into the distribution pool through the low flow resistance channel, and first fills the receiving chamber 02 near the connection between the multi-injection port 41 and the distribution pool 42. After filling, gradually fill the receiving chamber 02 away from the connection, which can ensure that when the sample amount is small, several receiving chambers 02 are filled, instead of filling all the receiving chambers 02, resulting in only partial filling of some or all of the receiving chambers 02, and the sample amount is closely related to the accuracy of subsequent detection, so the above structural limitation ensures the accuracy of detection.

[0046] like Figure 1 and Figure 2As shown, the microfluidic valve includes: a valve seat 1, which is located at the connection between the flow channel 01 and the accommodating chamber 02, and the flow channel 01, the valve seat 1 and the accommodating chamber 02 are successively away from the rotation center O, and the valve seat 1 has a sealing surface; a valve core 2, the density of the valve core 2 is less than the density of the sample liquid, and the valve core 2 has a spherical outer surface, and the spherical outer surface cooperates with the sealing surface to achieve sealing of the accommodating chamber 02.

[0047] When the liquid needs to flow, the liquid flows into the containing chamber through the microfluidic valve at a certain rotation speed of the microfluidic chip. Since the density of the valve core 2 is less than the density of the liquid, as the amount of liquid flowing into the containing chamber increases, under the dual effects of centrifugal force and buoyancy, the liquid pushes the valve core 2 to move toward the rotation center O until the inside of the containing chamber is filled. The valve core and the valve seat cooperate to seal the containing chamber. At this time, no liquid can enter the containing chamber, thereby achieving accurate quantification of the liquid in the containing chamber. At the same time, the design of the conventional microfluidic chip quantitative pool is avoided, and the size of the chip is reduced; secondly, the valve core can prevent the liquid from flushing the pre-stored reagent in the containing chamber to the downstream containing chamber during the process of entering each containing chamber in turn, thereby ensuring the reaction efficiency of each containing chamber and avoiding the upstream containing chamber. The overflow / flushed reagents in the reaction chamber will pollute the downstream containing chamber; secondly, the valve core can achieve the sealing of the chamber during the reaction without an external device, and the analysis is as follows: during the nucleic acid amplification reaction, as the temperature rises, the temperature of the liquid in the reaction chamber rises accordingly, and can continuously provide outward pressure to the valve core to ensure the sealing of the reaction chamber. Since no external device is required to seal the sealing element, the chip can rotate freely during the reaction, thereby realizing real-time collection of fluorescence data. At the same time, the optical elements of the instrument can be fixed, which simplifies the equipment and realizes low cost and miniaturization of the equipment; finally, after adopting the microfluidic valve of the present invention, the flow channel 01 can adopt a low flow resistance pipeline, and the sample transfer can be completed at a lower centrifugal speed, which reduces the requirements for the centrifugal equipment, and at the same time reduces the equipment cost and the chip preparation process requirements.

[0048] Since the containing chamber in the present invention is controlled by a microfluidic valve, accurate detection of the sample can be achieved without sealing the injection hole of the microfluidic chip, while also simplifying the manual operation process and improving detection efficiency.

[0049] In the present invention, the material of the valve core 2 is a flexible material, such as rubber, silicone, PDMS (abbreviation of polydimethylsiloxane, polydimethylsiloxane) and polyurethane material, etc., which can be a hydrophilic material or a hydrophobic material. In order to prevent the liquid from overflowing from the containing chamber or the liquid from flowing into the valve, the valve core 2 is preferably a hydrophobic material or a material with a hydrophobic surface treatment. In order to reduce the density of the valve core, a hollow flexible material or a foamed flexible material is used, such as a hollow polyurethane elastomer or a foamed polyurethane elastomer. Preferably, the tensile strength of the hollow or foamed flexible material is 5-10MPa, and the elongation at break is more than 500%.

[0050] In order to prevent the valve core from being too large and affecting the precision of liquid quantitative measurement in the accommodating chamber, the diameter of the valve core does not exceed 2 mm.

[0051] In order to further improve the sealing effect between the valve core and the valve seat, Figure 3 As shown, the sealing surface of the valve seat is a trapezoidal cylindrical surface 10, the small end 11 of the trapezoidal cylindrical surface is connected to the flow channel 01, the two hypotenuse angles a of the trapezoidal cylindrical surface 10 are 1-3°, and the large end 12 of the trapezoidal cylindrical surface is connected to the accommodating chamber; the ratio of the diameter of the small end of the trapezoidal cylindrical surface to the diameter of the valve core is in the range of 0.8-0.9, and the height h of the trapezoidal cylindrical surface is 2-4mm. The sealing surface of the valve seat is a trapezoidal cylindrical surface, and the two hypotenuse angles are small, which can increase the range of motion of the valve core in the valve seat. Even if the pressure fluctuation inside the accommodating chamber 02 during the subsequent operation of the microfluidic chip causes the range of motion of the valve core to increase, the liquid inside the accommodating chamber will not be connected to the liquid in the flow channel 01, thereby avoiding the problem of false positives caused by cross-contamination of different reaction pools or different reaction systems; secondly, the two hypotenuse angles are small, and cooperate with the valve core, so that the valve core will not slide from the small end of the trapezoidal cylindrical surface to the large end under the action of the trapezoidal cylindrical surface 10.

[0052] The valve seat in the present invention is made of the same material as the microfluidic chip body. In order to improve the sealing and isolation effect, the microfluidic chip body is made of hydrophobic material, or the sealing surface is subsequently hydrophobic treated. The hydrophobic treatment here is a conventional technology and will not be described in detail.

[0053] like Figure 4As shown, a compressible elastic component 3 is provided in the accommodating chamber 02 , and the elastic component 3 is located in the accommodating chamber, at a position away from the rotation center O relative to the valve seat 1 . By setting the elastic component 3, the valve core can be further pushed to move in the direction of the rotation center O. Specifically, when the microfluidic chip rotates, the liquid enters the interior of the accommodating chamber 02 through the flow channel 01 under the action of centrifugal force. When the liquid covers the elastic component 3, the liquid generates pressure on the elastic component 3 under the action of centrifugal force, so that the elastic component 3 is compressed, thereby forming a certain potential energy until the liquid pushes the valve core to the sealing surface of the valve seat; when the microfluidic chip stops rotating, the centrifugal force disappears, and the pressure acting on the elastic component 3 is released. The potential energy on the elastic component 3 continues to push the valve core 2 in the direction of the rotation center O. Since the sealing surface is a trapezoidal cylindrical surface, the pressure between the trapezoidal cylindrical surface 10 and the valve core 2 is increased, and the sealing effect is better; secondly, since the potential energy of the elastic component 3 depends on the centrifugal force of the liquid during rotation, different potential energies can be achieved by changing the position of the elastic component 3 inside the accommodating chamber. The present invention preferably sets the elastic component 3 at the bottom of the accommodating chamber.

[0054] Specifically, Figure 5 As shown, the elastic component 3 has an elastic membrane 30 and an outer wall 31, the elastic membrane 30 and the outer wall 31 form a sealed cavity 32, the elastic membrane 30 is located inside the accommodating cavity, and the outer wall 31 is fixedly connected to the accommodating cavity wall 020. In this embodiment, the elastic component 3 can be prepared first, and then fixedly connected to the accommodating cavity wall 020 by hot pressing, gluing, laser welding, ultrasonic welding, screw tightening, integral injection molding, etc.

[0055] Although the valve prepared in the above manner can largely isolate the liquid inside the receiving chamber from the liquid outside, when there is a compound inside the receiving chamber 02, there is a certain possibility that the mixture of the liquid and the compound will leak out of the receiving chamber during the process of injecting the liquid into the receiving chamber 02 through the flow channel 01. In order to solve the above problem, Figure 6 As shown, the elastic component 3 of the present invention is filled with a compound 33, the outer wall 31 has a fixed portion 310 connected to the elastic membrane, the non-fixed portion in the middle of the fixed portion area is convex to form a pressing portion 311, and the pressing portion 311 is provided with a piercing needle 312 on one side close to the sealing cavity, and the piercing needle 312 pierces the elastic membrane 30 by pressing the pressing portion.

[0056] It should be noted that compound 33 can be various reagents, primers, diluents, etc. Compounds here can be understood as various substances involved in the test process.

[0057] Specifically, Figure 7As shown, the puncture needle 312 has a connecting portion 3120 connected to the pressing portion 311 and a needle head 3121 connected vertically to the connecting portion 3120. When the pressing portion 311 is not pressed, the needle head 3121 is embedded in the groove of the fixing portion 310; when the pressing portion 311 is pressed, the needle head 3121 extends from the groove to puncture the elastic membrane 30, thereby releasing the compound in the sealed cavity 32. The needle head 3121 is embedded in the groove of the fixing portion 310, which ensures that the elastic membrane will not be punctured when not pressed; secondly, the possibility of cross-contamination in different reaction pools and different systems is further reduced. In order to improve the efficiency and success rate of puncturing the elastic membrane 30 when pressing, the blade tip of the elastic membrane is set on the upper side of the needle head 3121; during the pressing process, the needle head 3121 moves upward, and the blade tip directly contacts the elastic membrane to puncture it.

[0058] There is an elastic component 3 and a reactant arranged in the elastic component 3 in the scheme. The working principle of the microfluidic chip is: use an eight-row pipette to simultaneously add 8 different test samples with extracted nucleic acid to the eight-row injection holes, repeatedly blow and beat to dissolve the freeze-dried microspheres in the samples, and make the samples pass through the sample pool of the multiple injection ports 41 and the low-resistance fluid pipeline into the distribution pool 42, and then make the samples flow into the containing chamber 02 in sequence through the low-resistance fluid pipeline at a centrifugal speed of 1000rpm. When the sample flows into the reaction pool, the valve core 2 will float up to the proximal end of the receiving chamber 02 under the action of buoyancy and centrifugal force, so that it cooperates with the sealing surface of the valve seat to seal the receiving chamber, and the elastic component stores energy under the action of the centrifugal force of the liquid; when it stops rotating, the elastic component releases energy and continues to push the valve core to move toward the proximal end, so that the valve core passes over the stopper to form a stable seal; at this time, the pressing part 311 is pressed, and the needle 3121 pierces the elastic membrane 30, and the reactant enters the receiving chamber 02 to mix with the sample; similarly, the liquid enters other receiving chambers 02 in turn and achieves sealing, avoiding cross contamination between reaction pools caused by liquid swelling during the sample entering the reaction pool and the amplification reaction. The sample entering the receiving chamber 02 dissolves the freeze-dried primer and performs an amplification reaction under the conditions set by the detection instrument. After 20 minutes, the reaction is completed and the fluorescence in each reaction pool can be detected by the fluorescence recognition device in the instrument to obtain the results of the 6 designed indicators in the sample to be tested, thus realizing the joint detection of 6 indicators in 16 samples.

[0059] like Figure 8As shown, a stopper 13 is provided on the sealing surface of the valve seat; when the elastic membrane 30 changes from the squeezed state to the stretched state, the valve core at a position farther from the rotation center passes over the stopper 13 to reach a position closer to the rotation center. The stopper 13 can be a single or multiple protrusions on the trapezoidal cylindrical surface, used to stop the valve core 2. The stopper 13 can be provided in multiples at the same height of the trapezoidal cylindrical surface, or can be provided at different heights of the trapezoidal cylindrical surface.

[0060] Preferably, the sealing surface is a trapezoidal cylindrical surface, the small end of the trapezoidal cylindrical surface is connected to the flow channel, and the large end of the trapezoidal cylindrical surface is connected to the accommodating chamber; the stopper is annular, that is, it is formed by rotating around the axis of the trapezoidal cylindrical surface, and the annular plane is perpendicular to the axis of the trapezoidal cylindrical surface. When the stopper is set to be annular, the stopping effect on the valve core is improved, and the valve core is prevented from reciprocating in the trapezoidal cylindrical surface and coming out of the trapezoidal cylindrical surface when there is a large pressure fluctuation, resulting in sealing failure; secondly, the annular stopper is tightly fitted with the valve core to ensure the reliability of the seal.

[0061] like Fig. 9 , the cross-sectional shape of the annular stopper is a triangle, wherein the triangle faces the direction of the rotation center, with the trapezoidal cylindrical surface as the base, and the height H of the triangle is 1 / 10-1 / 5 of the diameter D2 of the circle formed by the plane formed by the vertices of the annular stopper and the line connecting the intersection points of the trapezoidal cylindrical surface. In the figure, D1 is the diameter of the plane formed by the annular stopper, and D2 is the diameter of the circle formed by the intersection of the plane of the annular stopper and the trapezoidal cylindrical surface; the diameter of the circle formed by the line connecting the plane formed by the vertices of the annular stopper and the intersection points of the trapezoidal cylindrical surface is not greater than the diameter of the valve core. Within the above parameter range, it is ensured that when the valve core passes over the triangular stopper to a position closer to the rotation center, the triangular stopper has a better non-return effect on the valve core; secondly, the direction of the triangle facing the rotation center is conducive to the valve core passing over the stopper from the distal end to the proximal end, which increases the difficulty of the valve core passing over the stopper from the proximal end to the distal end.

[0062] like Figure 10-12 As shown, different arrangements of multiple injection ports are shown.

[0063] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A microfluidic chip, characterized in that: include: A positioning hole, the positioning hole is used to connect with a detection instrument; A multiple injection port, wherein the number of the multiple injection port is at least one; A distribution pool, the distribution pool is connected to one of the multiple injection ports; A containing chamber, wherein the containing chamber comprises a plurality of chambers, each of which is connected to the distribution tank; The accommodating chamber is close to the rotation center and is provided with a microfluidic valve at a position communicating with the flow channel; The positioning hole, the multi-injection port, the distribution pool and the accommodating chamber are sequentially arranged away from the rotation center; The microfluidic valve comprises: A valve seat, the valve seat is located at the connection between the flow channel and the accommodating chamber, and the flow channel, the valve seat and the accommodating chamber are successively away from the rotation center, and the valve seat has a sealing surface; A valve core, wherein the density of the valve core is less than the density of the sample liquid, and the valve core has a spherical outer surface, and the spherical outer surface cooperates with the sealing surface to achieve sealing of the accommodating chamber; A compressible elastic component is provided in the accommodating chamber, and the elastic component is located in the accommodating chamber at a position away from the rotation center relative to the valve seat; The elastic component comprises an elastic membrane and an outer wall, the elastic membrane and the outer wall form a sealed cavity, the elastic membrane is located inside the accommodating cavity, and the outer wall is fixedly connected to the accommodating cavity wall; The sealing cavity is filled with a compound, the outer wall has a fixed portion connected to the elastic membrane, the non-fixed portion in the middle of the fixed portion area is convex to form a pressing portion, and a puncture needle is provided on the pressing portion close to the sealing cavity. By pressing the pressing portion, the puncture needle punctures the elastic membrane.

2. The microfluidic chip according to claim 1, characterized in that: The connection between the multi-injection port and the distribution pool is located at the circumferential end of the distribution pool around the rotation center, and the angle between the bottom surface of the distribution pool and the rotation center radially away from the connection is not greater than 90°.

3. The microfluidic chip according to claim 1, characterized in that: The valve core is made of hollow or foamed flexible material.

4. The microfluidic chip according to claim 1, characterized in that: The diameter of the valve core does not exceed 2 mm.

5. The microfluidic chip according to claim 1, characterized in that: The sealing surface is a trapezoidal cylindrical surface, the small end of the trapezoidal cylindrical surface is connected to the flow channel, the angle between the two hypotenuses of the trapezoidal cylindrical surface is 1-3°, and the large end of the trapezoidal cylindrical surface is connected to the accommodating chamber; The ratio of the diameter of the small end of the trapezoidal cylindrical surface to the valve core diameter is in the range of 0.8-0.9, and the height of the trapezoidal cylindrical surface is 2-4 mm.

6. The microfluidic chip according to claim 1, characterized in that: A stopper is provided on the sealing surface of the valve seat; When the elastic membrane changes from the squeezed state to the stretched state, the valve core at a position farther from the rotation center passes over the stopper and reaches a position closer to the rotation center.

7. The microfluidic chip according to claim 6, characterized in that: The sealing surface is a trapezoidal cylindrical surface, the small end of the trapezoidal cylindrical surface is connected to the flow channel, and the large end of the trapezoidal cylindrical surface is connected to the accommodating chamber; The stopper is annular, and the annular plane is perpendicular to the axis of the trapezoidal cylindrical surface.

8. The microfluidic chip according to claim 7, characterized in that: The cross-sectional shape of the stopper is a triangle, wherein the triangle faces the direction of the rotation center, takes the trapezoidal cylindrical surface as the base, and the height of the triangle is 1 / 10-1 / 5 of the diameter of the circle formed by the plane formed by the vertices of the stopper and the intersection line of the trapezoidal cylindrical surface; The diameter of the circle formed by the line connecting the intersection points of the plane formed by the vertices of the stopper and the trapezoidal cylindrical surface is not greater than the diameter of the valve core.

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