A new portable dot film instrument and a percolation immunochromatographic detection method

Abstract

The application relates to a novel portable point film instrument and a percolation immunochromatographic detection method. The novel portable point film instrument comprises a driving device and a point film device, the point film device is connected to the driving device; the driving device comprises a driving execution element and a sliding table; the point film device comprises a microsyringe, a moving part and a film loading table; the moving part is connected to the head part of a push rod of the microsyringe, the film loading table is arranged directly below a needle of the microsyringe, and the moving part is further fixedly connected to the sliding table, so that the moving part is driven to move up and down by the driving execution element, sample suction or point spraying of the microsyringe is realized, the drawbacks of a handheld pipette in a colloidal gold percolation immunochromatographic detection technology are eliminated, and problems such as human error and incapability of automation are solved. The application solves problems such as heaviness and incapability of portability of traditional immunochromatographic instruments.

Description

Technical Field

[0001] This invention relates to the field of colloidal gold percolation immunochromatographic detection technology, specifically a novel portable membrane coating instrument for coating antigens or antibodies on nitrocellulose percolation membranes. Background Technology

[0002] Colloidal gold immunochromatographic detection technology is one of the most widely used immunolabeling techniques in point-of-care testing. Its portability, ease of operation, speed, and the fact that it requires no specialized equipment or technicians have led to its widespread application in disease screening, food safety, and environmental monitoring.

[0003] Based on the reaction mode, colloidal gold immunochromatography can be divided into two types: lateralflow immunochromatography and vertical filtration immunochromatography. Lateralflow immunochromatography involves coating antigens or antibodies onto a nitrocellulose membrane (a film backing that cannot be filtered). The sample to be tested, along with the colloidal gold-labeled antibody or antigen, is chromatographically separated horizontally from the nitrocellulose membrane. The target in the sample is captured by the antigen or antibody coated on the nitrocellulose membrane, resulting in a red positive signal band. Due to the increased chromatography distance and reaction time, lateralflow immunochromatography requires more chromatography time than vertical filtration immunochromatography. This increases the probability of non-specific binding of non-specific substances in the sample to the colloidal gold label and the loss of the colloidal gold label, affecting specificity and sensitivity. It is worth noting that when the content of the target antigen or antibody in the sample is too high, lateralflow immunochromatography will exhibit severe back-band or front-band effects, leading to false negative results.

[0004] Vertical filtration immunochromatography is another immunochromatographic technique based on nitrocellulose membranes. These nitrocellulose membranes are nanoporous membranes without a film backing, allowing colloidal gold labels to easily permeate through the membrane. The nitrocellulose membrane is coated with antigens or antibodies. The sample is dropped onto the membrane, followed by the colloidal gold-labeled antibody or antigen. After washing with a washing buffer, the appearance of specific red spots on the membrane indicates the presence of the analyte in the sample. Compared to lateral flow immunochromatography, vertical filtration immunochromatography is faster, and the vertical chromatography mode avoids the front-and-back band effect present in lateral flow immunochromatography. Therefore, colloidal gold filtration immunochromatography technology is widely used in the detection of infectious diseases in humans and animals. Examples include the immunofiltration gold labeling method for detecting hepatitis B, hepatitis C, syphilis, and HIV disclosed in Chinese invention patent CN1164949C; the dotted gold filtration method for diagnosing schistosomiasis in livestock disclosed in Chinese invention patent CN1700008A; the dotted immunocolloidal gold filtration detection method for chicken infectious anemia virus antibodies disclosed in Chinese invention patent CN101059516A; the dotted immunogold directional filtration detection kit disclosed in Chinese invention patent CN102053153A; the dotted gold immunofiltration kit for detecting circulating antigens of Echinococcus multilocularis disclosed in Chinese invention patent CN102608321A; and the immunocolloidal gold filtration method for detecting Streptococcus agalactiae antibodies in tilapia disclosed in Chinese invention patent CN107942060A.

[0005] It is noteworthy that the coating of antigens or antibodies onto nitrocellulose membranes is a crucial process in establishing immunochromatographic detection methods. In lateral flow immunochromatography, the coating material is applied as streaks, while in vertical filtration immunochromatography, it is applied as circular dots. Since lateral flow immunochromatography uses a streak pattern for coating, there are already mature but cumbersome streak coating instruments on the market. However, to the best of the applicant's knowledge, there are no relevant dot-coating instruments for vertical filtration immunochromatography. Currently published Chinese invention patents (CN1164949C, CN1700008A, CN101059516A, CN102053153A, CN102608321A, CN107942060A) all involve manual pipette application for dot-coating, which significantly affects the uniformity of dot-coating within and between batches, increasing the difficulty of achieving quantification. Therefore, there is an urgent need for a new type of portable, economical and easy-to-operate film application device.

[0006] Therefore, the present invention provides a novel portable spotting instrument for use in colloidal gold percolation immunochromatographic detection technology. Summary of the Invention

[0007] This invention addresses the process requirements of current colloidal gold filtration immunochromatographic assays by providing a novel portable membrane application instrument to solve problems such as human error and lack of automation associated with traditional handheld pipette membrane coating of antigens or antibodies. Furthermore, this invention represents a significant effort in overcoming the issues of high cost, bulkiness, and lack of portability associated with traditional immunochromatographic instruments.

[0008] The principle of the colloidal gold filtration immunochromatographic detection technology involved in this invention is to use a nitrocellulose filtration membrane as a solid-phase carrier coated with antigen or antibody, and a colloidal gold-labeled antibody or antigen complex as a detection probe. If the purpose is to detect the antibody to be tested in the sample, an antigen-antibody-colloidal gold-labeled secondary antibody immune complex erythema will be formed on the nitrocellulose filtration membrane; if the purpose is to detect the antigen to be tested in the sample, a monoclonal antibody 1-antigen to be tested-colloidal gold-labeled monoclonal antibody 2 immune complex erythema will be formed on the nitrocellulose filtration membrane.

[0009] To solve the above-mentioned technical problems, the present invention is implemented through the following specific technical solutions:

[0010] In a first aspect, a novel portable membrane application device is used to apply coating liquid to a membrane in colloidal gold permeation immunochromatography; the novel portable membrane application device includes a driving device and a membrane application device, wherein the membrane application device is connected to the driving device.

[0011] The driving device includes a driving actuator and a slide table. The slide table is connected to the driving actuator and is driven to move up and down by the driving actuator.

[0012] The membrane dispensing device includes a micro-injector, a movable part, and a membrane stage. The movable part is connected to the plunger head of the micro-injector, and the membrane stage is located directly below the needle of the micro-injector. The membrane stage has a circular groove and a sample suction hole located in the circular groove. The permeate membrane can be selectively placed in the circular groove. The movable part is also fixedly connected to the slide, so that the movable part can be moved up and down by the drive actuator to realize the sample suction or dispensing of the micro-injector.

[0013] In this invention, the driving device and the film-dip device are fixedly connected by screws.

[0014] In this invention, the driving device further includes a housing, a battery, a driver, a controller, a power supply switch, and a touch switch disposed within the housing. The controller is connected to the battery via the power supply switch, the driving actuator is connected to the controller via the driver, and the touch switch is connected to the controller.

[0015] In this invention, the controller is further provided with a speed knob and / or an acceleration knob.

[0016] In this invention, the output shaft of the drive actuator is a helical column, the slide is threadedly connected to the helical column, and the drive actuator drives the helical column to rotate so as to move the slide up and down.

[0017] In this invention, the driving device further includes a slide docking bayonet, which is detachably mounted on the slide; the moving part is fixed between the slide and the slide docking bayonet.

[0018] In this invention, the driving actuator is a stepper motor.

[0019] In this invention, the distance between the surface of the permeation membrane placed in the circular groove and the needle of the micro-injector is 0.5~1mm.

[0020] In this invention, the dot film device further includes a housing, and an embedding groove is provided on the side of the housing for embedding the micro-injector.

[0021] Secondly, a percolation immunochromatographic detection method includes the following steps:

[0022] (1) Extraction and purification of the coating antigen;

[0023] (2) Detection of antibodies using colloidal gold labeling;

[0024] (3) Preparation of the washing solution;

[0025] (4) Preparation of gold standard solution;

[0026] (5) Provide the above-mentioned novel portable membrane applicator, insert a centrifuge tube loaded with coating solution containing the coating antigen of step (1) into the sampling port from the bottom, and ensure that the needle of the microsyringe is inserted below the liquid surface; drive the microsyringe to aspirate the coating solution; remove the centrifuge tube from the sampling port, and load the permeate membrane into the circular groove on the membrane stage; drive the microsyringe to spray the coating solution on the permeate membrane.

[0027] Remove the permeate membrane after application and dry it;

[0028] Load the permeation membrane and absorbent paper onto the permeation card shell, place the absorbent paper at the bottom of the permeation membrane, and assemble the colloidal gold permeation immunochromatographic detection card.

[0029] (6) Testing steps:

[0030] Mix the sample to be tested with the washing solution in step (3), and drop it onto the permeate membrane of the test card in step (5). Then drop the gold labeling solution in step (4) onto the membrane. The washing solution is dropped onto the membrane to clean the reaction background. If red spots appear on the membrane, it is a positive result; otherwise, it is a negative result.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention eliminates the drawbacks of handheld pipette application in colloidal gold filtration immunochromatographic assays, resolving issues such as human error and the inability to automate the process. It also addresses the problem of bulky and unportable traditional immunochromatographic instruments, achieving a truly compact and portable application device that significantly reduces instrument costs and overcomes the issue of high prices associated with traditional immunochromatographic instruments.

[0033] This novel portable coating applicator is based on a drive unit consisting of a 12V rechargeable battery, a stepper motor, a driver, a controller, a rocker-shaped two-prong switch, and a touch switch. It cleverly uses a microsyringe as the coating pump and incorporates 3D printing technology for the assembly and interoperability of parts, enabling the coating of antigens or antibodies onto nitrocellulose membranes. Compared to bulky, expensive, and cumbersome traditional coating applicators, this invention is smaller (12cm × 10cm × 27cm), lower in cost, and easier to carry, allowing operators to perform portable coating in various scenarios. Furthermore, the applicator is simple to operate, without complicated procedures. Simply insert the needle of the microsyringe into a microcentrifuge tube containing coating solution, press the touch switch to load the sample; pressing the touch switch again sprays the loaded coating solution onto the nitrocellulose membrane on the membrane stage, facilitating antigen or antibody coating. Furthermore, the present invention can control the dispensing volume and speed of the portable membrane dispensing device by replacing different models of micro-injectors, adjusting the speed and acceleration knobs on the controller, and the limit switch, so as to meet the requirements of antigen or antibody coating on the nitrocellulose filtration membrane in real time. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a front view schematic diagram of the novel portable film application device of the present invention;

[0036] Figure 2 This is a rear view schematic diagram of the novel portable film application device of the present invention;

[0037] Figure 3 This is a front view structural diagram of the driving device of the novel portable film application instrument of the present invention. The sliding table docking bayonet is hidden in the figure.

[0038] Figure 4 This is an exploded view of the driving device of the novel portable film application instrument of the present invention.

[0039] Figure 5 This is a schematic diagram of the internal structure assembly of the drive device of the novel portable film application instrument of the present invention;

[0040] Figure 6 This is a side view of the dispensing device of the novel portable dispensing device of the present invention;

[0041] Figure 7 This is an exploded view of the film application device of the novel portable film application instrument of the present invention;

[0042] Figure 8 for Figure 7 Enlarged view of point A in the middle;

[0043] Figure 9 This is a schematic diagram of the sample aspiration process of the novel portable film application instrument of the present invention. Implementation

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The reference herein to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the application. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0045] As described in the background section, the drawbacks of handheld pipette application in colloidal gold filtration immunochromatographic assay can be eliminated, and problems such as human error and lack of automation can be solved. To address these issues, a novel portable application instrument is proposed.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. It is worth emphasizing that the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0047] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to disclose some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] It should be noted that, without conflict, features and technical solutions of different embodiments in this invention can be combined with each other.

[0049] It should be noted that the same reference numerals denote the same items in the following figures. Therefore, once an item is defined with a reference numeral in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] like Figures 1 to 9 As shown, a novel portable film application device includes two parts: a drive unit 1 and a film application device 2, which are assembled and fixed together by screws.

[0051] The outermost layer of the drive unit 1 is the shell 101, which is made of PLA material obtained through 3D printing technology. It is economical and readily available, and has the characteristics of being lightweight and having high hardness, making it convenient for operators to carry.

[0052] A stepper motor 102 is vertically mounted on the front of the housing 101. The stepper motor 102 has a slide 105 that passes through the spiral column 103 and the slide rod 104. The stepper motor 102 can stop moving when it touches a limit sensor at its top or bottom. A rocker-shaped two-prong switch 106 and a touch switch 107 are respectively mounted on the left and right sides of the stepper motor 102. Inside the housing 101 are a 12V rechargeable battery 108, a driver 109, a controller 110, and wiring. The battery 108 is connected to the controller 110 via the rocker-shaped two-prong switch 106, and the stepper motor 102 is connected to the controller 110 via the driver 109. Furthermore, the speed knob 112, acceleration knob 113, limit switch 114, and USB charging interface of the 12V rechargeable battery 108 on the controller 110 are all externally displayed on the back cover 111 for easy operator control. The speed knob 112, acceleration knob 113, and limit switch 114 on the controller 110 can adjust the film application speed, acceleration, and number of applications. The back cover 111 of the drive unit 1 fits perfectly with the outer shell 101, encapsulating the above components within the shell. The travel distance of the stepper motor 102 matches the range scale length of the microsyringe 203, enabling a single-pass sample aspiration to fully load the microsyringe 203 and a single-pass film application to completely release the coating solution. The rechargeable battery 108 can be connected to the USB charging interface for power storage, eliminating the drawback of traditional immunochromatographic instruments requiring 220V AC power.

[0053] The touch switch 107 is used as the driving switch for the film dispensing instrument. It has the feature of automatic reset. After a single click of the touch switch 107, only one sample aspiration or film dispensing command is generated.

[0054] The membrane application device 2 has an integrated housing 201. The front of the housing 201 has a vertically oriented embedding groove 202 that matches the shape of the micro-injector 203 for loading the micro-injector 203. When changing to a micro-injector 203 with a different volume range, the micro-injector 203 can be removed from this embedding groove 202 for replacement. At the bottom of the front of the housing 201, a horizontally oriented membrane stage 204 is provided for loading the nitrocellulose filtration membrane. The membrane stage 204 has a circular groove 205 in the center, and a concentric, slightly smaller circular aspiration hole 206 at the center of the circular groove 205, allowing a 250μL centrifuge tube to be vertically inserted for sample aspiration.

[0055] The drive unit 1 and the dosing device 2 are vertically fixed by screws. The head of the push rod 2031 of the micro-injector 203 is connected to a movable part 207, which is detachably mounted on the slide table 105 via a slide table docking slot 115. The slide table docking slot 115 has a groove 116 that matches the movable part 207. In addition, the slide table 105 has a cylindrical groove 117, and the slide table docking slot 115 has a cylindrical protrusion 118 that matches the cylindrical groove 117 on the slide table 105. The three parts are assembled to fix the movable part 207 on the slide table 105 and receive power from the stepper motor 102. Obviously, when changing micro-injectors 203 with different ranges, these three parts need to be disassembled.

[0056] The distance between the nitrocellulose permeation membrane placed on the membrane stage 204 and the needle 2032 of the microsyringe 203 is 0.5~1mm.

[0057] The specific working process of the novel portable film application device provided by this invention is as follows:

[0058] like Figure 9 As shown, when using this device, first turn on the boat-shaped two-prong switch 106 to power the electronic drive device 1. Adjust the speed knob 112, acceleration knob 113, and limit switch 114 to the appropriate positions as needed, and move the slide table 105 to the bottom of the stepper motor. Then, pass a 250μL centrifuge tube containing the coating solution through the sampling port 206 from the bottom of the membrane stage 204 until the needle 2032 of the microsyringe 203 is inserted below the liquid surface. Click the touch switch 107 to draw the coating solution into the microsyringe 203, remove the 250μL centrifuge tube 3, load the nitrocellulose membrane into the circular groove 205 in the membrane stage 204, and click the touch switch 107 again to spray the coating solution onto the membrane. Remove the nitrocellulose membrane, dry it at 37°C, and store it in a sealed container.

[0059] To test and evaluate the coating area that the device of the present invention can form on a nitrocellulose permeation membrane using microsyringes of different capacities, 0.5 μL, 1 μL, 5 μL, and 10 μL microsyringes were loaded onto a membrane application instrument. Based on purified Brucella lipopolysaccharide as the coating antigen and colloidal gold-labeled Streptococcus protein G as the detection probe, a Brucella antibody colloidal gold permeation immunochromatographic assay card was established. The coating area was determined by measuring the diameter of the positive erythema spots formed by the application of microsyringes with different capacities onto the membrane.

[0060] Based on the extracted and purified Brucella lipopolysaccharide antigen as the coating antigen on the nitrocellulose permeation membrane and the colloidal gold-labeled Streptococcus protein G as the detection probe, a Brucella antibody permeation immunochromatographic detection card was established to evaluate the performance of a novel portable membrane dispensing instrument of the present invention.

[0061] A Brucella antibody filtration immunochromatographic detection method:

[0062] (1) Extraction and purification of Brucella lipopolysaccharides:

[0063] Add 100 mL of Brucella selective medium purchased from Haibo Biotechnology to an Erlenmeyer flask, add 1 mL of Brucella bacterial culture, and incubate at 37°C for 18-24 h (all operations in this step were performed in a BSL-3 laboratory). Centrifuge the resulting bacterial culture at 12000 g for 30 min, collect 5 mL of bacterial clumps, add 1 mL of Lysis Buffer, and vortex until the clumps dissolve. Add 1 mL of chloroform, shake for 1 min, let stand at room temperature for 5 min, centrifuge at 12000 g for 30 min, collect the supernatant, add 1 mL of 1 mg / mL proteinase K, and incubate overnight at 4°C. Centrifuge the overnight mixture at 12000 g for 30 min, collect the precipitate, wash three times with 75% ethanol, and finally dissolve in 20 mM Tiris-HCl (pH 8.0).

[0064] (2) Colloidal gold-labeled streptococcal protein G

[0065] Measure 200 mL of deionized water into a conical flask and heat to boiling. Add 0.4 mL of 5% chloroauric acid trihydrate to the flask. After boiling again, quickly add 1 mL of 8% sodium citrate and boil for 30 min. Cool to room temperature and store at 4°C. Take 1 mL of the prepared colloidal gold solution into a 1.5 mL centrifuge tube, adjust the pH to 6.0-6.5, add 20 μg of streptococcal protein G, vortex to mix, and label for 20 min. Then add 100 μL of 10% BSA, vortex to mix, and block for 20 min. Centrifuge the colloidal gold complex at 12000 g for 15 min and dissolve in 0.1 mL of reconstitution solution (5% sucrose, 5% trehalose, 1% BSA, 10 mM PBS, pH 7.4).

[0066] (3) Preparation of washing solution:

[0067] 2% Tween 20 dissolved in 10mM PBS, pH 7.4.

[0068] (4) Preparation of gold standard solution:

[0069] Each 100 μL of washing solution contains 3 μL of colloidal gold-labeled streptococcal protein G.

[0070] (5) Provide a new portable film application device, which is operated according to the following steps:

[0071] Adjust the speed and acceleration knobs to ensure the dispensing apparatus is at a suitable dispensing speed. Adjust the limit switch so that a single click activates the switch, allowing the microsyringe to aspirate or spray the membrane in a single operation. Load 0.5 μL, 1 μL, 5 μL, and 10 μL microsyringes onto the dispensing apparatus to test and evaluate the coating area that the microsyringes of this invention can form on the nitrocellulose permeate membrane at different volume ranges.

[0072] Insert a 250 μL centrifuge tube containing an appropriate amount of Brucella lipopolysaccharide coating solution into the aspiration well from the bottom, ensuring that the needle of the microsyringe is inserted below the liquid surface;

[0073] Turn on the two-prong switch of the spot film instrument to power the drive unit, click the touch switch, and the micro syringe will draw up the coating solution;

[0074] Remove the 250μL centrifuge tube from the sample aspiration port and load the appropriately sized nitrocellulose membrane into the circular groove on the membrane stage.

[0075] Click the touch switch, and the membrane applicator will spray the coating solution from the micro-syringe onto the nitrocellulose filtration membrane.

[0076] Remove the nitrocellulose permeation membrane after application and dry it at 37°C.

[0077] The nitrocellulose membrane and absorbent paper are loaded onto the permeation card shell, with the absorbent paper placed at the bottom of the nitrocellulose membrane, and the colloidal gold permeation immunochromatographic assay card is assembled.

[0078] (6) Colloidal gold permeation immunochromatographic assay card detection steps:

[0079] Mix 10 μL of the sample to be tested with 90 μL of washing solution and drop it onto the nitrocellulose filtration membrane of the test card. Then, drop 100 μL of gold-labeled solution onto the membrane. Immediately afterward, drop 100 μL of washing solution onto the membrane to wash away the reaction background. If red spots appear on the membrane, it is a positive result; otherwise, it is a negative result.

[0080] The coating area corresponding to micro-syringes with different ranges loaded on the novel portable dosing device provided by this invention is shown in Table 1.

[0081] Table 1. Relationship between volume range and coating area of ​​microsyringe

[0082] Microsyringe volume range (μL) 0.5 1.0 5.0 10.0 Coverage area (mm) 0.5 1 3 5

[0083] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A new portable spot film apparatus characterized in that, It is used to spray coating liquid onto the permeation membrane of colloidal gold permeation immunochromatography for permeation immunochromatographic detection; the novel portable membrane dispensing instrument includes a driving device and a membrane dispensing device, the membrane dispensing device being connected to the driving device. The driving device includes a driving actuator and a slide table. The slide table is connected to the driving actuator and the driving actuator drives the slide table to move up and down. The membrane dispensing device includes a micro-injector, a movable part, and a membrane stage. The movable part is connected to the push rod head of the micro-injector, and the membrane stage is located directly below the needle of the micro-injector. The membrane stage has a circular groove and a sample suction hole located in the circular groove. The permeation membrane can be selectively placed in the circular groove. The movable part is also fixedly connected to the slide table so that the movable part can be moved up and down by the drive actuator to realize the sample suction or dispensing of the micro-injector. The process of spraying the coating solution onto the membrane of colloidal gold percolation immunochromatography for detection includes the following steps: (1) Extraction and purification of the coating antigen; (2) Detection of antibodies using colloidal gold labeling; (3) Preparation of the washing solution; (4) Preparation of gold standard solution; (5) Provide the novel portable membrane dispensing instrument, adjust the speed knob and acceleration knob to control the dispensing volume and dispensing speed of the portable membrane dispensing instrument; adjust the limit switch so that the micro-injector can aspirate or spray the membrane once by clicking the switch; load 0.5μL, 1μL, 5μL and 10μL micro-injectors on the membrane dispensing instrument respectively, and test and evaluate the coating area that the micro-injectors loaded with different ranges can form on the nitrocellulose permeation membrane; Insert the centrifuge tube containing the coating solution with the coating antigen of step (1) into the sampling port from the bottom, ensuring that the needle of the micro-syringe is inserted below the liquid surface; drive the micro-syringe to aspirate the coating solution; remove the centrifuge tube from the sampling port and load the permeate membrane into the circular groove on the membrane stage; drive the micro-syringe to spray the coating solution onto the permeate membrane. Remove the permeate membrane after application and dry it; Load the permeation membrane and absorbent paper onto the permeation card shell, place the absorbent paper at the bottom of the permeation membrane, and assemble the colloidal gold permeation immunochromatographic detection card. (6) Testing steps: Mix the sample to be tested with the washing solution in step (3), drop it onto the permeate membrane of the test card in step (5), then drop the gold labeling solution in step (4) onto the membrane, and drop the washing solution onto the membrane to clean the reaction background. If red spots appear on the membrane, it is a positive result; otherwise, it is a negative result. The drive device and the film dispensing device are fixedly connected by screws; The drive device also includes a housing, and a battery, a driver, a controller, a power switch, and a touch switch disposed within the housing. The controller is connected to the battery via the power switch, the drive actuator is connected to the controller via the driver, and the touch switch is connected to the controller. The controller is also equipped with a speed knob and an acceleration knob.

2. The new portable film poinier according to claim 1, characterized in that, The output shaft of the driving execution element is a screw column, the sliding table is threadedly connected to the screw column, and the driving execution element drives the screw column to rotate to drive the sliding table to move up and down.

3. The new portable film thickness gauge according to claim 1, characterized in that, The driving device further comprises a sliding table butt joint socket which is detachably installed on the sliding table; and the moving part is fixed between the sliding table and the sliding table butt joint socket.

4. The new portable film thickness gauge according to claim 1, characterized in that, The driving execution element is a stepping motor.

5. The new portable film thickness gauge according to claim 1, characterized in that, The distance between the surface of the percolation membrane placed in the circular groove and the needle of the micro-injector is 0.5-1 mm.

6. The new portable film thickness gauge according to claim 1, characterized in that, The point membrane device further comprises a shell, and the side edge of the shell is provided with an embedding groove for embedding the micro-injector.

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