A fluorescent immunochromatographic test strip for detecting free IgE

Abstract

This invention relates to a fluorescent immunochromatographic test strip for detecting free IgE, comprising a base plate, a sample pad disposed on the base plate, a conjugate pad, a detection membrane, and an absorbent material sequentially overlapped on the base plate, as well as a detection line and a control line disposed on the detection membrane; the fluorescent immunochromatographic test strip for detecting free IgE further includes a filter membrane disposed on the base plate, with one end overlapping the sample pad and the other end overlapping the conjugate pad; the filter membrane is coated with mouse anti-human IgG monoclonal antibody, the conjugate pad is coated with fluorescent microsphere-labeled FcERI antigen and fluorescent microsphere-labeled DNP-BSA, the detection line is coated with mouse anti-human IgE antibody, and the control line is coated with DNP monoclonal antibody. This fluorescent immunochromatographic test strip has advantages such as high sensitivity, high accuracy, good stability, good repeatability, and ease of operation, and has broad application prospects.

Description

Technical Field

[0001] This utility model relates to the field of immunofluorescence detection technology, specifically to a fluorescent immunochromatographic test strip for detecting free IgE. Background Technology

[0002] Free IgE refers to immunoglobulin E (IgE) in serum that is not bound to cells. IgE is one of the most abundant immunoglobulins in human serum and plays an important role in type I hypersensitivity reactions, also known as allergic reactions. IgE can bind to high-affinity IgE receptors (FcεRI) on the surface of effector cells (such as mast cells and basophils). When allergens re-enter the body, they can trigger these cells to release inflammatory mediators such as histamine, leading to allergic symptoms.

[0003] In the treatment of allergic diseases such as asthma, the application of anti-IgE antibodies, such as omalizumab, is of great significance. Omalizumab is a recombinant 95% humanized monoclonal anti-IgE antibody that inhibits the release of inflammatory mediators by binding to free IgE, preventing IgE from binding to high-affinity IgE receptors on the surface of effector cells, thereby achieving therapeutic goals. Furthermore, the use of omalizumab can reduce the level of free IgE and downregulate the expression of FcεRI on the surface of effector cells, thus weakening the effector effect of IgE. Therefore, the detection of free IgE helps to further understand the clinical efficacy of omalizumab and is of important guiding significance for identifying specific allergens in patients, assessing symptom severity, and guiding the clinical use of omalizumab.

[0004] Currently, enzyme-linked immunosorbent assay (ELISA) is the most common method for detecting free IgE in clinical and laboratory settings. However, ELISA suffers from poor precision, sensitivity, and linearity, and is also characterized by numerous steps and long processing times. While fluorescent immunochromatographic test strips offer advantages such as short detection time and ease of use, there are currently no reports or commercially available products specifically designed for detecting free IgE. Summary of the Invention

[0005] The purpose of this invention is to provide a fluorescent immunochromatographic test strip for detecting free IgE.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] This invention provides a fluorescent immunochromatographic test strip for detecting free IgE, comprising a base plate, a sample pad disposed on the base plate, a conjugate pad, a detection membrane, and an absorbent material sequentially overlapped on the base plate, as well as a detection line and a control line disposed on the detection membrane; the fluorescent immunochromatographic test strip for detecting free IgE further comprises a filter membrane disposed on the base plate, with one end overlapping the sample pad and the other end overlapping the conjugate pad;

[0008] The filter membrane is coated with mouse anti-human IgG monoclonal antibody, the binding pad is coated with fluorescent microsphere-labeled FcERI antigen and fluorescent microsphere-labeled DNP-BSA, the detection line is coated with mouse anti-human IgE antibody, and the control line is coated with DNP monoclonal antibody.

[0009] According to some specific embodiments, the sample pad is made of glass cellulose membrane.

[0010] According to some specific embodiments, the filter membrane is made of nitrocellulose membrane.

[0011] According to some specific embodiments, the material of the bonding pad is a glass cellulose membrane.

[0012] According to some specific embodiments, the detection membrane is made of nitrocellulose membrane.

[0013] According to some specific embodiments, the base plate is a PVC board; the absorbent material is absorbent paper.

[0014] According to some specific embodiments, at the overlap between the sample pad and the filter membrane, the sample pad is located above the filter membrane; at the overlap between the filter membrane and the bonding pad, the bonding pad is located above the filter membrane.

[0015] According to some specific embodiments, the length of the sample pad is 10-20 mm, the length of the filter membrane (3) is 4-10 mm, the length of the conjugate pad (4) is 4-8 mm, the length of the detection membrane (5) is 25 mm, and the distance between the detection line (6) and the quality control line (7) is 4-8 mm.

[0016] According to some specific embodiments, the width of the fluorescent immunochromatographic test strip for detecting free IgE is 3.9 mm.

[0017] According to some specific embodiments, the fluorescent immunochromatographic test strip for detecting free IgE further includes an ID card fixedly disposed on the fluorescent immunochromatographic test strip for detecting free IgE, wherein the ID card stores calibration data and / or standard curves.

[0018] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0019] This novel fluorescent immunochromatographic test strip can rapidly quantify free IgE in a single test with minimal clinical sample usage and only one fluorescent immunoassay analyzer. It also boasts advantages such as high sensitivity, high accuracy, good stability, good repeatability, and ease of operation, making it a promising candidate for widespread application. Attached Figure Description

[0020] Figure 1 This invention relates to a fluorescent immunochromatographic test strip for detecting free IgE.

[0021] The components include: 1. Sample pad; 2. Base plate; 3. Filter membrane; 4. Conjugate pad; 5. Detection membrane; 6. Detection line; 7. Quality control line; 8. Absorbent paper. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] In the description of the embodiments of this utility model, it should be understood that the terms "front," "back," "up," and "down," etc., are directional terms used in the context of... Figure 1 The orientations are defined as follows: the side where sample pad 1 is located is left, the side where absorbent paper 8 is located is right, the side where base plate 2 is located is down, and the opposite side is up. The above directional terms are only for the convenience of describing the embodiments of this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this utility model.

[0025] The following disclosure provides many different implementations or examples for different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0026] Figure 1A fluorescent immunochromatographic test strip for detecting free IgE is shown, comprising a base plate 2, a sample pad 1, a filter membrane 3, a conjugate pad 4, a detection membrane 5, and absorbent paper 8 sequentially disposed on the base plate 2, and a detection line 6 and a control line 7 disposed on the detection membrane 5. The left end of the filter membrane 3 overlaps with the right end of the sample pad 1, and the right end overlaps with the left end of the conjugate pad 4; the right end of the conjugate pad 4 overlaps with the left end of the detection membrane 5, and the right end of the detection membrane 5 overlaps with the left end of the absorbent paper 8. Furthermore, at the overlap between the sample pad 1 and the filter membrane 3, the sample pad 1 is positioned above the filter membrane 3; at the overlap between the filter membrane 3 and the conjugate pad 4, the conjugate pad 4 is positioned above the filter membrane 3; at the overlap between the conjugate pad 4 and the detection membrane 5, the conjugate pad 4 is positioned above the detection membrane 5; and at the overlap between the detection membrane 5 and the absorbent paper 8, the absorbent paper 8 is positioned above the detection membrane 5. The detection line 6 is to the left of the control line 7.

[0027] The filter membrane 3 is coated with mouse anti-human IgG monoclonal antibody, the conjugate pad 4 is coated with fluorescent microsphere-labeled FcERI antigen and fluorescent microsphere-labeled DNP-BSA, the detection line 6 is coated with mouse anti-human IgE antibody, and the control line 7 is coated with DNP monoclonal antibody.

[0028] The base plate 2 is made of PVC, the sample pad 1 and the conjugate pad 4 are both made of glass cellulose membrane, and the filter membrane 3 and the detection membrane 5 are both made of nitrocellulose membrane.

[0029] The sample pad 1 has a length of 10–20 mm, the filter membrane 3 has a length of 4–8 mm, the conjugate pad 4 has a length of 4–8 mm, and the detection membrane 5 has a length of 25 mm; the distance between the detection line 6 and the control line 7 is 4–8 mm. In one embodiment, the sample pad 1 has a length of 12 mm, the filter membrane 3 has a length of 10 mm, the conjugate pad 4 has a length of 7 mm, and the detection membrane 5 has a length of 25 mm; the distance between the detection line 6 and the control line 7 is 6 mm. The width of the fluorescent immunochromatographic strip for detecting free IgE is 3.9 mm. The thicknesses of the base plate 2, sample pad 1, filter membrane 3, conjugate pad 4, detection membrane 5, and absorbent paper 8 can be conventional thicknesses in the art.

[0030] The fluorescent immunochromatographic test strip for detecting free IgE also includes an ID card, which is placed on the fluorescent immunochromatographic test strip for detecting free IgE. The ID card stores calibration data and / or standard curves.

[0031] The fluorescent immunochromatographic test strip for detecting free IgE has sample application wells (not shown in the figure). The assembly of the fluorescent immunochromatographic test strip, i.e., how the sample pad 1, filter membrane 3, conjugate pad 4, detection membrane 5 and absorbent paper 8 are fixed on the base plate 2, the overlap length between the sample pad 1 and the filter membrane 3, and the setting of the sample application wells, are all conventional techniques in this field and will not be described in detail here.

[0032] The experimental materials used in the embodiments of this utility model are all conventional experimental materials in the art and can be purchased through commercial channels. The mouse anti-human IgG monoclonal antibody, fluorescent microspheres, FcERI antigen, DNP-BSA, mouse anti-human IgE antibody, and DNP monoclonal antibody used in the embodiments are all commercially available products. The methods for labeling FcERI antigen and DNP-BSA with fluorescent microspheres are prior art.

[0033] In the following examples and comparative examples, the fluorescence immunoassay analyzer used is the DL300 dry fluorescence immunoassay analyzer manufactured by Dialabo (Zhangjiagang) Biotechnology Co., Ltd.

[0034] The specific usage method includes the following steps:

[0035] (1) Insert the fluorescent immunochromatographic test strip into the fluorescent immunoassay analyzer, read the calibration data and / or standard curve on the ID card, and remove the fluorescent immunochromatographic test strip after reading.

[0036] (2) The sample to be tested can be selectively diluted with sample diluent. The undiluted or diluted sample to be tested is dropped onto the fluorescent immunochromatographic test strip and allowed to stand for 5 min to 15 min. The undiluted or diluted sample to be tested passes through the sample pad 1, filter membrane 3, conjugate pad 4, and detection membrane 5 in sequence to reach the absorbent paper 8.

[0037] (3) Insert the fluorescent immunochromatographic test strip after static reaction back into the fluorescent immunoassay analyzer, read the fluorescence intensity of the detection line 6 and the control line 7, and calculate and output the free IgE concentration value of the sample to be tested based on the calibration data and / or standard curve.

[0038] In this invention, the sample to be tested on the fluorescent immunochromatographic test strip is a serum sample.

[0039] Compared to test strips that omit the filter membrane 3, the fluorescent immunochromatographic test strip of this invention has better sensitivity, accuracy, stability and repeatability.

[0040] The test strip with the filter membrane 3 omitted has the following structure: Sample pad 1, conjugate pad 4, detection membrane 5, and absorbent paper 8 are sequentially overlapped at a specific position on the base plate 2. After assembly, it is cut to a fixed width of 3.9 mm to obtain a fluorescent immunochromatographic test strip for detecting free IgE. The mouse anti-human IgG monoclonal antibody, which was originally coated on the filter membrane 3, is now coated on the sample pad 1.

[0041] This novel fluorescent immunochromatographic test strip can rapidly quantify free IgE in a single test with minimal clinical sample usage and only one fluorescent immunoassay analyzer. It also boasts advantages such as high sensitivity, high accuracy, good stability, good repeatability, and ease of operation, making it a promising candidate for widespread application.

[0042] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fluorescent immunochromatographic test strip for detecting free IgE, comprising a base plate (2), a sample pad (1) disposed on the base plate (2), a conjugate pad (4), a detection membrane (5), and an absorbent material sequentially overlapped on the base plate (2), and a detection line (6) and a control line (7) disposed on the detection membrane (5); characterized in that: The fluorescent immunochromatographic test strip for detecting free IgE also includes a filter membrane (3) disposed on the base plate (2) with one end overlapping the sample pad (1) and the other end overlapping the conjugate pad (4); The filter membrane (3) is coated with mouse anti-human IgG monoclonal antibody, the conjugate pad (4) is coated with fluorescent microsphere-labeled FcERI antigen and fluorescent microsphere-labeled DNP-BSA, the detection line (6) is coated with mouse anti-human IgE antibody, and the control line (7) is coated with DNP monoclonal antibody.

2. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The sample pad (1) is made of glass cellulose membrane.

3. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The filter membrane (3) is made of nitrocellulose membrane.

4. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The material of the bonding pad (4) is glass cellulose membrane.

5. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The detection membrane (5) is made of nitrocellulose membrane.

6. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The base plate (2) is a PVC board; the absorbent material is absorbent paper (8).

7. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: At the overlap between the sample pad (1) and the filter membrane (3), the sample pad (1) is located above the filter membrane (3); at the overlap between the filter membrane (3) and the bonding pad (4), the bonding pad (4) is located above the filter membrane (3).

8. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The sample pad (1) is 10-20 mm long, the filter membrane (3) is 4-10 mm long, the conjugate pad (4) is 4-8 mm long, and the detection membrane (5) is 25 mm long; the distance between the detection line (6) and the quality control line (7) is 4-8 mm.

9. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The width of the fluorescent immunochromatographic strip for detecting free IgE is 3.9 mm.

10. The fluorescent immunochromatographic test strip for detecting free IgE according to claim 1, characterized in that: The fluorescent immunochromatographic test strip for detecting free IgE also includes an ID card fixedly mounted on the fluorescent immunochromatographic test strip for detecting free IgE, wherein the ID card stores calibration data and / or standard curves.

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