A microfluidic control cartridge

Abstract

The present invention discloses a microfluidic control cartridge, which belongs to the field of immunoassay technology, including a cartridge upper cover, a cartridge lower cover, a detection membrane, a waterproof microfluidic plate, and blotting paper. The microfluidic plate moves between the cartridge upper cover and the cartridge lower cover so that the liquid permeates the chip and is absorbed by the blotting paper. The microfluidic cartridge of the present invention controls the reaction time of the protein loaded on the paper chip by designing the microfluidic plate, and designs a water absorbing device under the microfluidic plate. When the reaction is completed, the microfluidic plate is pulled, and the liquid permeates the chip and is sucked off by the blotting paper. Therefore, the microfluidic cartridge of the present invention can control the flow and storage time of microfluids, so that the protein loaded on the chip can fully react with various antigens or antibodies and chromogenic substrates in steps. There can be many kinds of proteins loaded on the chip, which can be arranged in the form of a microarray. The reaction time of the microfluid and the protein chip can be controlled by the microfluidic plate.

Description

Technical Field

[0001] The invention relates to the technical field of immunoassay, and in particular to a microfluidic control cartridge. Background Art

[0002] Immunoassay reactions involve many steps, each step requires a guaranteed reaction time, and the unreacted interferences must be washed away before the next step can proceed. In addition, clinical samples have potential biological contamination. Existing immunoassay reaction devices are difficult to perform high-throughput tests, and require a large amount of clinical specimens, which is very traumatic for patients.

[0003] The existing implementation scheme that is closest to the invention is the 96-well enzyme-linked immunosorbent assay plate, but it does not have a liquid adsorption device, requires manual plate washing, is easy to pollute the environment, and is also difficult to achieve micro-volume high-throughput detection.

[0004] Another solution is colloidal gold chip filtration cartridge, but it cannot control the retention time of the fluid-chip reaction, so sensitive detection cannot be achieved.

[0005] At the same time, the existing immunoassay technology usually uses a 96-well polystyrene plate, which uses the adsorption of polystyrene to proteins to coat antigens or antibodies in microwells. During the reaction, the test liquid containing antigens and antibodies is added to the microwells for incubation. After the reaction, the liquid is manually removed and washed, and then a secondary antibody or protein containing a marker that can react with the test protein is added. The reaction is incubated for a certain period of time. After the reaction, the residual liquid is manually removed and washed, and then a color substrate is added. The reaction is color-developed and the value is read. It takes multiple rounds of incubation and washing processes, and the operation steps are complicated. The waste liquid is also easy to pollute the environment. The detection throughput is low. If the throughput needs to be increased, parallel experiments can only be performed, and the sample quantity requirements are high.

[0006] Therefore, it is necessary to design a new microfluidic control cartridge to solve the above technical problems. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a microfluidic control card. To solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: a microfluidic control card, including a card cover, a card cover, a liquid-permeable detection membrane, a water-proof microfluidic plate, and absorbent paper. The card cover is detachably connected to the card cover, and a downwardly concave window for embedding the detection membrane is provided on the card cover. The detection membrane is fixedly connected to the card cover with four small protrusions. The sliding groove of the microfluidic plate is arranged between the card cover and the card cover. The shape of the sliding groove is U-shaped. When the microfluidic plate is inserted, the three sides of the microfluidic plate are tightly fitted with the sliding groove to isolate water, and the baffle part is just stuck in the gap formed by the upper and lower card covers for the movement of the microfluidic plate. Therefore, the upper card shell and the microfluidic plate can form a cup shape for carrying the reaction liquid. The absorbent paper is located on one side of the microfluidic plate close to the lower cover of the card housing, the lower cover of the card housing is used to store absorbent materials, the uppermost part is covered with absorbent paper, or the entire cover is covered with absorbent paper. The microfluidic plate moves between the detection membrane and the absorbent paper.

[0008] In order to greatly improve the detection effect of the detection membrane, as a preferred microfluidic control cartridge of the present invention, the detection membrane is a nitrocellulose membrane.

[0009] In order to greatly improve the high-throughput detection effect of the protein array, as a preferred microfluidic control cartridge of the present invention, the nitrocellulose membrane can be stamped or sprayed with multiple protein arrays for realizing high-throughput detection.

[0010] In order to greatly improve the high-throughput detection effect of the protein array, as a preferred microfluidic control cartridge of the present invention, there is a small protrusion under the window of the cartridge cover, which can fix the detection membrane and achieve a positioning effect.

[0011] In order to greatly improve the stability and detection effect of the protein array, as a preferred microfluidic control cartridge of the present invention, the protein array is evenly arranged at equal intervals on one side of the nitrocellulose membrane close to the cartridge cover.

[0012] In order to greatly improve the stability and detection effect of the protein array, as a preferred microfluidic control cartridge of the present invention, the protein spots are arranged in an array on one side of the nitrocellulose membrane close to the cartridge cover.

[0013] In order to greatly improve the limiting ability of the track groove on the microfluidic plate, as a preferred microfluidic control cartridge of the present invention, a track groove is provided between the cartridge upper cover and the cartridge lower cover to facilitate the movement of the microfluidic plate.

[0014] In order to greatly improve the control and operation capabilities of the microfluidic plate, as a preferred microfluidic control card shell of the present invention, the microfluidic plate includes a control part for controlling the microfluidic plate and a limiting part for limiting the movement position of the microfluidic plate, and a baffle part for preventing liquid from flowing out, and the control part, the baffle part and the limiting part are fixedly connected.

[0015] In order to greatly improve the limiting ability between the limiting portion and the track groove, as a preferred microfluidic control cartridge of the present invention, the cross-sectional area of ​​the limiting portion plus the microfluidic plate fitted thereto is larger than the cross-sectional area of ​​the microfluidic plate.

[0016] In order to greatly control the distance the microfluidic plate is pulled out and make the liquid easily absorbed by the absorbent paper under the window, as a preferred microfluidic control cartridge of the present invention, the limiting portion is located near the top of the microfluidic plate, and its width is smaller than the distance from the edge of the cartridge upper cover window to the corresponding upper cover edge.

[0017] In order to greatly improve the airtightness of the microfluidic plate, as a preferred microfluidic control cartridge of the present invention, the microfluidic control plate is designed with a baffle portion for forming a closed bearing cavity between the microfluidic plate and the upper cartridge when the microfluidic plate is pushed in.

[0018] In order to greatly improve the overall stability between the control part and the limiting part, as a preferred microfluidic control cartridge of the present invention, the control part is a baffle part protruding outward, suitable for finger grasping and easy to operate.

[0019] In order to greatly improve the carrying capacity of liquid, as a preferred microfluidic control cartridge of the present invention, the microfluidic plate and the cartridge upper cover are closed to form a cavity for carrying liquid.

[0020] After adopting the above technical scheme, the present invention has the following beneficial effects compared with the prior art.

[0021] The present invention provides a microfluidic control cartridge including a cartridge upper cover, a cartridge lower cover, a detection membrane, a microfluidic plate with water-proof properties, and absorbent paper. The microfluidic plate moves in a track groove between the cartridge upper cover and the cartridge lower cover so that a liquid permeates a chip and is absorbed by the absorbent paper. The microfluidic cartridge of the present invention controls the reaction of liquid with a protein loaded on a paper chip by designing a microfluidic plate, and a water absorbing device is designed under the microfluidic plate. After the reaction is completed, the microfluidic plate is pulled, and the liquid permeates the chip and is sucked off by the absorbent paper. At the same time, the microfluidic cartridge of the present invention can control the flow and storage time of microfluids. The protein loaded on the chip can fully react with various antigens or antibodies and color-developing substrates in steps. There can be many kinds of proteins loaded on the chip, which can be arranged in the form of a microarray. The reaction time of the microfluid and the protein chip can be controlled by the microfluidic plate, and the immune reaction, washing, color development and other operation steps are realized by the microfluidic plate and the absorbent paper under the plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a microfluidic control cartridge of the present invention;

[0023] Figure 2 A schematic structural diagram of an embodiment of a microfluidic control cartridge of the present invention;

[0024] Figure 3 It is a schematic diagram of the analysis of a microfluidic control cartridge of the present invention;

[0025] In the figure, 100, the upper cover of the card shell; 200, the lower cover of the card shell; 210, the track groove; 300, the detection membrane; 301, the small protrusion; 302, the window; 310, the protein array; 400, the microfluidic plate; 410, the control part; 420, the limit part; 430, the baffle part; 500, the absorbent paper. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] See also Figures 1 to 3 The present invention provides a technical solution: a microfluidic control cartridge, comprising a cartridge upper cover 100, a cartridge lower cover 200, a detection membrane 300, a waterproof microfluidic plate 400, and a wicking paper 500. The cartridge upper cover 100 is detachably connected to the cartridge lower cover 200. A window for embedding the detection membrane is provided on the cartridge upper cover. A small convex column 301 is provided under the window 302 of the cartridge upper cover to fix the detection membrane and achieve a positioning effect. The detection membrane 300 is fixedly connected to the cartridge upper cover window 302 through the small convex column 301. 2, the slide rail of the microfluidic plate 400 is arranged between the upper cover 100 of the card shell and the lower cover 200 of the card shell, and the detection membrane 300 is arranged between the upper cover window 302 of the card shell and the microfluidic plate 400, the absorbent paper 500 is attached to the side of the microfluidic plate 400 close to the lower cover 200 of the card shell, the lower cover 200 of the card shell is used to contain absorbent materials, and the microfluidic plate 400 moves between the upper cover 100 of the card shell and the lower cover 200 of the card shell, so that the liquid permeates the chip and is absorbed by the absorbent paper 500.

[0029] Example 1: Antigens of bacteria and viruses commonly causing respiratory infections were spotted in a microarray on a 1 cm2 nitrocellulose membrane: influenza B virus, syncytial virus, adenovirus, Mycoplasma pneumoniae antigen, Legionella, Q fever Rickettsia, Chlamydia pneumoniae, influenza A virus, and parainfluenza virus. The uncoated sites were then blocked with PBS containing 10% fire-killing bovine serum. After drying, the membrane was assembled on the lower side of the window 302 of the microfluidic card cover 100 to make a respiratory nine-item human serum IgG detection card. During the test, the patient's serum is diluted with PBS at a ratio of 1:10, and 200 microliters of the diluted serum is added to the depression formed at the window 302 of the upper cover of the microfluidic test card, so that the serum reacts with the chip for 30 minutes, and the microfluidic plate 400 is pulled out, so that the reaction liquid is absorbed by the absorbent paper 500 under the microfluidic plate 400, and then 200 microliters of PBS is added, washed, and also absorbed by the absorbent paper 500; the microfluidic plate 400 is inserted, and colloidal gold-labeled sheep anti-human IgG polyclonal antibody reaction liquid is added to the chip cover, so that the gold liquid reacts with the antigen-antibody complex on the chip for 30 minutes, and the microfluidic plate 400 is pulled out, and the unreacted colloidal gold liquid is absorbed by the absorbent paper 500 stored in the lower cover 200 of the card shell, and then 200 microliters of PBS containing 10% BSA is added, washed, and the washing liquid is absorbed by the absorbent paper 500. The NC membrane window with a thickness of 100 mm on the microfluidic cartridge can produce colloidal gold-red spots for positive results and no spots for negative results according to the reaction conditions. With 20 microliters of serum, 9 viral IgG antibody tests can be completed at one time, and the operation is simple and the sensitivity is not lower than ELISA.

[0030] Example 2: Preparation and screening of specific antibody pairs against 9 respiratory antigens including influenza B virus, syncytial virus, adenovirus, Mycoplasma pneumoniae antigen, Legionella, Q fever Rickettsia, Chlamydia pneumoniae, influenza A virus, and parainfluenza virus, and detection of the antigens using the double antibody sandwich method.

[0031] Antibodies corresponding to nine respiratory antigens were spotted on a nitrocellulose membrane in the form of a microarray, and then the uncoated sites were blocked with PBS containing 10% fire-killing bovine serum. After drying, it was assembled into a microfluidic card shell to make a respiratory nine-antigen detection card. During the test, the patient's throat swab is diluted to 200 microliters with PBS containing 0.05% Tween-20, and added to the depression formed at the window 302 of the upper cover of the microfluidic test card, so that the sample reacts with the chip for 30 minutes, and the microfluidic plate 400 is pulled out, and the reaction liquid is absorbed by the absorbent paper 500 under the microfluidic plate 400, and then 200 microliters of PBS is added, washed, and also absorbed by the absorbent paper 500; the microfluidic plate 400 is inserted, and 300 microliters of colloidal gold mixed solution labeled with 9 different mouse anti-respiratory antigen monoclonal antibodies is added to the upper cover of the chip, and the gold liquid is reacted with the antigen-antibody complex on the chip for 30 minutes, and the microfluidic plate 400 is pulled out, and the unreacted colloidal gold liquid is absorbed by the absorbent paper 500 stored in the lower cover 200 of the card shell, and then 200 microliters of PBS containing 10% BSA is added, washed, and the washing liquid is absorbed by the absorbent paper 500. The NC membrane window with a thickness of 100 mm on the microfluidic cartridge can produce colloidal gold-red spots in a positive case and no spots in a negative case according to the reaction conditions. With a throat swab sample, nine virus tests can be completed at one time, and the operation is simple and the sensitivity is not lower than ELISA.

[0032] Example 3: Antigens of bacteria and viruses that commonly infect the respiratory tract were spotted in the form of microarray on a nitrocellulose membrane: influenza B virus, syncytial virus, adenovirus, Mycoplasma pneumoniae antigen, Legionella, Q fever Rickettsia, Chlamydia pneumoniae, influenza A virus, parainfluenza virus, and these 9 antigens, and then the uncoated sites were blocked with PBS containing 10% fire-killing bovine serum. After drying, it was assembled into a microfluidic card shell to make a respiratory tract nine-item human serum IgM test card. During the test, the microfluidic plate 400 is inserted, the patient's serum is diluted with PBS at a ratio of 1:10 to become 200 microliters of liquid, and the liquid is added to the depression formed at the window of the upper cover of the microfluidic test card, so that the serum reacts with the chip for 30 minutes, and the microfluidic plate 400 is pulled out, so that the reaction liquid is absorbed by the absorbent paper 500 under the microfluidic plate 400, and then 200 microliters of PBS is added, and the reaction liquid is washed three times, and the reaction liquid is also absorbed by the absorbent paper 500; the microfluidic plate 400 is inserted, and the goat anti-human IgM polyclonal antibody labeled with horseradish peroxidase is added to the upper cover of the chip, so that the secondary antibody reacts with the antigen-antibody complex on the chip for 30 minutes, and the microfluidic plate 400 is pulled out, and the unreacted secondary antibody liquid is absorbed by the absorbent paper 500 stored in the lower cover 200 of the card shell, and then 200 microliters of PBS containing 10% BSA is added, and the reaction liquid is washed three times, and the washing liquid is absorbed by the absorbent paper 500. Insert the microfluidic plate 400, then add DAB substrate solution, control the color reaction time, and pull open the microfluidic plate 400 after the reaction is completed. The excess liquid is absorbed by the absorbent paper 500. The NC membrane window 100 on the microfluidic card shell can produce colored spots for positive and no spots for negative according to the reaction situation. With 20 microliters of serum, 9 viral IgM antibody tests can be completed at one time, and the operation is simple and the sensitivity is not lower than ELISA.

[0033] As a technical optimization solution of the present invention, the detection membrane 300 is a nitrocellulose membrane.

[0034] At the same time, the window 302 of the card housing cover 100 is lower than the upper frame of the card housing cover 100 but higher than the lower frame. The detection membrane 300 can be embedded in the window 302, and the four walls of the card housing cover 100 and the microfluidic plate 400 can form a closed cup shape for carrying liquid.

[0035] In this embodiment, the application of nitrocellulose membrane can improve the detection effect of the detection membrane 300 .

[0036] As a technical optimization solution of the present invention, a plurality of protein arrays 310 for realizing high-throughput detection can be arranged on the nitrocellulose membrane.

[0037] In this embodiment, the arrangement of multiple protein arrays 310 can further improve the high-throughput detection effect of the protein array 310 .

[0038] As a technical optimization solution of the present invention, the protein array 310 is evenly arranged at equal intervals on a side of the nitrocellulose membrane close to the card housing upper cover 100 .

[0039] In this embodiment, the equally spaced protein array 310 can improve the stability and detection effect of the protein array 310 .

[0040] As a technical optimization solution of the present invention, the protein array 310 is arranged irregularly on a side of the nitrocellulose membrane close to the card housing upper cover 100 .

[0041] In this embodiment, the irregular protein array 310 can improve the stability and detection effect of the protein array 310 .

[0042] As a technical optimization solution of the present invention, the upper cover 100 and the lower cover 200 of the card housing are provided with a track groove 210 for preventing the microfluidic plate 400 from moving out.

[0043] In this embodiment, the track groove 210 can improve the limiting capability of the microfluidic plate 400 .

[0044] As a technical optimization solution of the present invention, the microfluidic plate 400 includes a control unit 410 for controlling the microfluidic plate 400 and a limiter 420 for limiting the movement position of the microfluidic plate 400, and the control unit 410 and the limiter 420 are fixedly connected.

[0045] In this embodiment, the cooperation between the control part 410 and the limiting part 420 can improve the control and operation capabilities of the microfluidic plate 400 .

[0046] As a technical optimization solution of the present invention, the cross-sectional area of ​​the limiting portion 420 plus the microfluidic plate attached thereto is larger than the cross-sectional area of ​​the microfluidic plate.

[0047] In this embodiment: the size of the blocked position and the limiting portion 420 and the track groove 210 can improve the limiting ability of the microfluidic plate 400. The microfluidic plate 400 is similar to a drawer without four-sided plates. The cross-section of the limiting portion 420 plus the microfluidic plate fitted therewith is larger than the cross-section of the microfluidic plate 400. The excess area is below the microfluidic plate 400 to prevent the microfluidic plate 400 from sliding out of the stuck slide rail. At the same time, the limiting portion 420 is located near the top of the microfluidic plate 400, and its width is less than the horizontal distance from the edge of the window to the edge of the corresponding upper cover to ensure that the microfluidic plate 400 can be completely pulled out to avoid the position of the window 302 to avoid affecting the absorption of liquid by the window 302.

[0048] As a technical optimization solution of the present invention, the control part 410 has a baffle part 430 protruding outwards, which is suitable for being grasped by fingers.

[0049] In this embodiment, the control parts 410 and the limiting parts 420 of different shapes can improve the overall stability of the movement of the microfluidic plate 400.

[0050] As a technical optimization solution of the present invention, a cavity for carrying liquid is formed between the microfluidic plate 400 and the four walls of the card housing upper cover 100.

[0051] In this embodiment: the cavity can improve the carrying capacity of the present invention for liquid.

[0052] Working principle:

[0053] The present invention provides a microfluidic control card shell, including a card shell upper cover 100, a card shell lower cover 200, a detection membrane 300, a microfluidic plate 400 with water-proof properties, and absorbent paper 500. The card shell upper cover 100 is provided with a window 302 for embedding the detection membrane 300, the edge of the window 302 forms a slope with the edge of the card shell upper cover 100, and the window 302 is concave downward, the detection membrane 300 is fixedly connected to the window 302 by four small protrusions 301 at the bottom of the window 302 downward, the window 302 is on the upper side of the microfluidic plate 400, the microfluidic plate 400 moves between the card shell upper cover 100 and the card shell lower cover 200, so that liquid permeates the chip and is absorbed by the absorbent paper 500, and the microfluidic plate 4 00 and the four walls of the card shell cover 100 can form a cavity for carrying liquid. At the same time, the bottom of the microfluidic plate 400 is an absorbent material, which can absorb the waste liquid after the reaction. The chip carrier is a liquid-permeable nitrocellulose membrane, which is located above the microfluidic plate 400 and fixes and supports the protein microarray. The microfluidic plate 400 can also be plastic or metal or kraft paper. The microfluidic plate 400 controls the reaction of the liquid with the protein loaded on the paper chip. A water absorption device is designed under the microfluidic plate 400. When the reaction is completed, the microfluidic plate 400 is pulled, and the liquid penetrates the chip and is absorbed by the absorbent paper 500.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microfluidic control cartridge, characterized in that: include: A card case upper cover (100), a card case lower cover (200), a detection membrane (300), a waterproof microfluidic plate (400), and absorbent paper (500), wherein the card case upper cover (100) and the card case lower cover (200) are detachably connected, a window (302) for embedding the detection membrane (300) is provided on the card case upper cover (100), an edge of the window (302) and an edge of the card case upper cover (100) form a slope, and the window (302) is concave downward to form a cavity for storing liquid, and the detection membrane (300) is fixedly connected to the window (302) through four small protrusions (301) at the bottom of the window (302) downward. The microfluidic plate (400) is slidably disposed between the upper cover (100) and the lower cover (200) of the card housing, and the sliding movement of the microfluidic plate (400) between the upper cover (100) and the lower cover (200) of the card housing can cause liquid to be retained in the cavity or penetrate the chip and be absorbed by the absorbent paper (500), the detection membrane (300) is disposed on the lower side of the window (302) of the upper cover (100) of the card housing, the absorbent paper (500) is located on a side of the microfluidic plate (400) close to the lower cover (200) of the card housing, and the lower cover (200) of the card housing is used to store absorbent material; The microfluidic plate (400) comprises a control part (410) for controlling the microfluidic plate (400), a limiting part (420) for limiting the movement position of the microfluidic plate (400), and a baffle part (430) for preventing liquid from flowing out, wherein the control part (410), the baffle part (430) and the limiting part (420) are fixedly connected; The detection membrane (300) is a sheet-like support material that can filter water and adsorb proteins.

2. A microfluidic control cartridge according to claim 1, characterized in that: The detection membrane is a nitrocellulose membrane, and different samples are fixed on the detection membrane using a chip instrument to carry a protein array (310) for high-throughput detection.

3. A microfluidic control cartridge according to claim 2, characterized in that: The protein array (310) is evenly arranged at equal intervals on a side of the nitrocellulose membrane close to the card housing upper cover (100).

4. A microfluidic control cartridge according to claim 3, characterized in that: The protein array (310) is irregularly arranged on a side of the nitrocellulose membrane close to the card housing upper cover (100).

5. The microfluidic control cartridge according to claim 1, characterized in that: The housing lower cover (200) and the housing upper cover (100) are provided with a track groove (210) for the movement of the microfluidic plate (400). The thickness of the track groove (210) is the same as the thickness of the microfluidic plate. The microfluidic plate (400) can move in the track groove (210) to achieve fluid control.

6. The microfluidic control cartridge according to claim 1, characterized in that: The cross-sectional area of ​​the limiting portion (420) plus the microfluidic plate (400) attached thereto is greater than the cross-sectional area of ​​the microfluidic plate (400).

7. A microfluidic control cartridge according to claim 6, characterized in that: The control portion (410) is to protrude outward from the baffle portion (430) so as to be suitable for being grasped by fingers.

8. A microfluidic control cartridge according to claim 7, characterized in that: The microfluidic plate (400) and the card housing upper cover (100) can be closed to form a cavity for carrying liquid.

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