Colloidal gold test strip and kit for detecting human parathyroid hormone and application of colloidal gold test strip and kit

Abstract

The invention belongs to the technical field of biomedical detection, and particularly relates to a colloidal gold test strip for detecting human parathyroid hormone, a kit and application of the colloidal gold test strip. The colloidal gold test strip can be arranged according to a conventional colloidal gold test strip, and the colloidal gold test strip at least comprises a capture antibody and a detection antibody. The test strip provided by the invention can realize instant detection of suspected parathyroid gland tissues in thyroid surgery, does not need sample pretreatment, has the detection result not interfered by low-concentration PTH in blood, is simple and convenient to operate and reliable in result, provides an intraoperative decision-making auxiliary tool for surgeons, reduces the parathyroid gland mis-cutting rate and the occurrence rate of postoperative hypofunction, and has a good application prospect. And the method has good practical application value.

Description

Technical Field

[0001] This invention belongs to the field of biomedical detection technology, specifically relating to a colloidal gold test strip, reagent kit, and their applications for detecting human parathyroid hormone. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] The parathyroid glands are endocrine glands located on the dorsal side of the thyroid gland. They primarily secrete parathyroid hormone (PTH), which regulates calcium and phosphorus homeostasis in the body. Due to their small size, similar color to surrounding tissues, and variable location, they are easily mistakenly removed during thyroid surgery. Misremoval or damage to the parathyroid glands can lead to PTH deficiency, causing transient or permanent hypocalcemia, manifesting as perioral / hand and foot numbness, spasms, convulsions, and even arrhythmias. Currently, there is no effective treatment, making it one of the main causes of medical disputes in thyroid surgery.

[0004] The current clinical method for parathyroid gland identification is intraoperative frozen section pathology, which takes over 30 minutes, prolonging the operation time. Furthermore, parathyroid tissue is prone to inactivation when preserved at room temperature outside the body, and the tissue loss during examination also reduces the success rate of autologous transplantation. The clinical incidence of transient hypoparathyroidism is 5.6% to 57.1%, while the incidence of permanent hypoparathyroidism is 0% to 12.8%. Therefore, there is an urgent need to develop a rapid, accurate, and tissue-loss-free intraoperative parathyroid gland identification technique.

[0005] However, the inventors discovered that while existing immunochromatographic test strips can achieve rapid detection of biomarkers, there are still shortcomings in test strips for intraoperative parathyroid tissue detection: conventional test strips cannot directly process tissue fragments and require pretreatment steps such as centrifugation, dilution, or premixing with specific buffer solutions, which are cumbersome and inconvenient for intraoperative implementation; antibody pairs are easily interfered with by low concentrations of PTH in the blood, making it difficult to balance specificity and sensitivity; and there is a lack of a quality control system suitable for rapid intraoperative detection, resulting in insufficient reliability of test results. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a colloidal gold test strip, a reagent kit, and their applications for the direct detection of exudate from human parathyroid tissue. Specifically, this invention provides a colloidal gold test strip for rapid intraoperative confirmation of human parathyroid glands, enabling immediate detection of suspected parathyroid tissue during thyroid surgery. It requires no sample pretreatment, the results are unaffected by low concentrations of PTH in the blood, and the operation is simple and reliable. This provides surgeons with an intraoperative decision-making aid, reducing the rate of incorrect parathyroid gland removal and the incidence of postoperative functional decline. This invention is based on the above research findings.

[0007] Specifically, the present invention relates to the following technical solutions:

[0008] In a first aspect, the present invention provides a colloidal gold test strip for detecting human parathyroid hormone, the colloidal gold test strip being configured as a conventional colloidal gold test strip, the colloidal gold test strip comprising at least a capture antibody and a detection antibody; The amino acid sequences of the heavy chain variable regions CDR-H1, CDR-H2, and CDR-H3 of the capture antibody AB1 are shown in SEQ ID NO.2-4, respectively; and the amino acid sequences of the light chain variable regions CDR-L1, CDR-L2, and CDR-L3 are shown in SEQ ID NO.6-8, respectively. The amino acid sequences of the heavy chain variable regions CDR-H1, CDR-H2 and CDR-H3 of the detection antibody AB2 are shown in SEQ ID NO.10-12, respectively; and the amino acid sequences of the light chain variable regions CDR-L1, CDR-L2 and CDR-L3 are shown in SEQ ID NO.14-16, respectively. Specifically, the amino acid sequence of the heavy chain variable region of the capture antibody AB1 is as shown in SEQ ID NO.1, or has at least 80% homology with SEQ ID NO.1; more preferably, it has at least 90% homology; most preferably, it has at least 95% homology; such as having at least 96%, 97%, 98%, or 99% homology. The capture antibody AB1 has an amino acid sequence of the variable region of its light chain as shown in SEQ ID NO.5, or has at least 80% homology with SEQ ID NO.5; more preferably, it has at least 90% homology; most preferably, it has at least 95% homology; such as having at least 96%, 97%, 98%, or 99% homology. The detection antibody AB2 has an amino acid sequence of the variable region of its heavy chain as shown in SEQ ID NO.9, or has at least 80% homology with SEQ ID NO.9; more preferably, it has at least 90% homology; most preferably, it has at least 95% homology; such as having at least 96%, 97%, 98%, or 99% homology. The detection antibody AB2 has an amino acid sequence of the variable region of its light chain as shown in SEQ ID NO.13, or has at least 80% homology with SEQ ID NO.13; more preferably, it has at least 90% homology; most preferably, it has at least 95% homology; such as having at least 96%, 97%, 98%, or 99% homology.

[0009] The capture and detection antibodies are paired rabbit monoclonal antibodies. Compared to traditional mouse antibodies, rabbit monoclonal antibodies offer advantages in stability, batch-to-batch consistency, and large-scale production, helping to reduce production costs and ensure the reliability of reagent performance. They specifically recognize the N-terminal and mid-segment antigenic epitopes of the PTH molecule, respectively, and their binding is independent, forming a stable "AB1-PTH-AB2-colloidal gold" double-antibody sandwich complex. These antibodies have been optimized for affinity screening and are unaffected by low concentrations of PTH in the blood, showing a positive result only when high concentrations of PTH are detected in parathyroid tissue exudate. This facilitates rapid intraoperative confirmation of human parathyroid glands.

[0010] In another specific embodiment of the present invention, the colloidal gold test strip includes: a base plate, on which a sample pad, a colloidal gold binding pad, a detection pad and an absorbent pad are sequentially disposed, with adjacent pads overlapping and connected at the joint.

[0011] The base plate can be cardboard or PVC board, without specific limitations, and serves to ensure structural stability.

[0012] The sample pad is a glass fiber membrane treated with a phosphate buffer containing 1-5% BSA and a surfactant, used to optimize sample flow rate and reduce non-specific adsorption. The surfactant may be Tween-20, with a concentration of 0.1-1%.

[0013] The colloidal gold conjugate pad uses a glass fiber membrane as its base, on which a colloidal gold-conjugated detection antibody AB2 is coated.

[0014] The detection pad uses a nitrocellulose membrane as its base, on which control lines and detection lines are sequentially arranged. The detection lines are coated with capture antibody AB1, and the control lines are coated with goat anti-rabbit IgG.

[0015] The absorbent pad can be an absorbent board or an absorbent cotton pad, and no specific limitation is made here.

[0016] Furthermore, to meet the need for direct intraoperative detection of tissue debris and exudate, a filter membrane is placed at the interface between the sample pad and the colloidal gold-bound pad. This filter membrane effectively separates tissue debris and blood cells, allowing tissue fluid components to pass through smoothly and reducing interference. The filter membrane can be a cellulose membrane with a pore size controlled at 4-10 μm, such as 5, 6, 7, 8, or 9 μm.

[0017] The detection principle of the colloidal gold test strip is as follows: During detection, the sample is dropped onto the sample pad. If the sample contains a high concentration of PTH (e.g., >500 pg / mL), it first binds to the AB2 antibody on the colloidal gold binding pad during chromatography, forming a "PTH-AB2-colloidal gold" complex. This complex continues chromatography to the detection line (T line) on the nitrocellulose membrane, where it is captured by the capture antibody AB1 fixed on the line, forming an "AB1-PTH-AB2-colloidal gold" double-antibody sandwich complex. The colloidal gold aggregates and develops color, with the color depth positively correlated with the PTH concentration. The unbound AB2-colloidal gold complex continues to the control line (C line), where it is captured and developed color by goat anti-rabbit IgG, indicating that the chromatography process is complete.

[0018] A second aspect of the present invention provides a kit comprising at least the above-described colloidal gold test strip for detecting human parathyroid hormone. Further, in the kit, the colloidal gold test strip also has a casing.

[0019] A third aspect of the present invention provides the use of the above-described colloidal gold test strip or kit in any one or more of the following: (a) Detecting parathyroid hormone or preparing products for detecting parathyroid hormone; (b) Identify parathyroid tissue or prepare a product that identifies parathyroid tissue.

[0020] The beneficial technical effects of one or more of the above technical solutions: (1) The above technical solution adopts an optimized immunochromatographic system, and the sample chromatography only takes 5-10 minutes to produce results, which greatly shortens the detection time compared with traditional frozen pathological examination, and avoids the prolongation of operation time and in vitro inactivation of parathyroid tissue; (2) Adding tissue debris and red blood cell filter membranes can directly detect the broken exudate / suspension supernatant of suspected parathyroid tissue without the need for pretreatment steps such as centrifugation and purification, which is suitable for emergency detection scenarios during surgery. (3) Using sequence-optimized rabbit monoclonal antibody pairs, different PTH antigenic epitopes are identified respectively. It only shows colorimetric results for high concentrations of PTH in parathyroid tissue exudate, and is not affected by low concentrations of PTH in blood. Blood samples and other tissue exudates are negative. The lowest detectable concentration is 500 pg / mL, and the positive detection rate of repeated tests is 100%. (4) Set up quality control lines to verify the chromatography process, avoid false negative results caused by operation, test strip failure, etc., and provide a reliable basis for intraoperative diagnosis; (5) Only a small amount of tissue exudate / suspension is needed for the test, and there is no need to cut tissue samples for testing. The complete parathyroid tissue is preserved for autologous transplantation, which improves the success rate of transplantation. (6) Rabbit monoclonal antibodies are used, which have advantages over traditional mouse antibodies in terms of stability, batch-to-batch consistency and large-scale production, reducing production costs and ensuring stable reagent performance. In summary, the above-mentioned technical solutions can achieve rapid and accurate identification of parathyroid glands during surgery, helping doctors to immediately determine whether suspected tissue is parathyroid glands, minimizing the risk of misremoval, and fundamentally reducing the incidence of transient and permanent hypoparathyroidism after thyroid surgery. It has significant clinical and social value. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 This is a standard curve of ELISA used for the quantitative detection of parathyroid hormone concentration in this invention.

[0023] Figure 2 The graph shows the results of five concentration gradients in this invention: test strip 1, 1:10, 1:100, 1:1000, 1:1000, 1:10000, and negative control.

[0024] Figure 3 This is a diagram showing the test results of blood and lymph node exudate according to the present invention; the sample to be tested on the test strip on the left is blood, and the sample to be tested on the test strip on the right is lymph node exudate. Detailed Implementation

[0025] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, 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 pertains.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Experimental methods in the following specific embodiments, unless specific conditions are specified, are generally performed according to conventional methods and conditions in molecular biology within the art, which are fully explained in the literature. See, for example, the techniques and conditions described in Sambrook et al., *Molecular Cloning: A Laboratory Manual*, or according to the conditions recommended by the manufacturer.

[0027] The following examples further illustrate the present invention, but do not constitute a limitation thereof. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] Example 1: Preparation and characterization of specific rabbit monoclonal antibody pairs 1. Animal immunization New Zealand white rabbits were systematically immunized using full-length human parathyroid hormone (PTH) protein as an immunogen: For the primary immunization, 200-300 μg of antigen was emulsified with an equal volume of adjuvant and injected subcutaneously at multiple sites on the rabbit's back; a first booster immunization was administered 3-4 weeks after the primary immunization, followed by booster immunizations every 2-3 weeks for a total of 4 doses; blood samples were collected one week after the final immunization, and the antiserum titer reached 1×10⁻⁶. 6 The above successfully induced a high-titer specific humoral immune response.

[0029] 2. Lymphocyte preparation and monoclonalization Three to four days after the last immunization, rabbit spleens were aseptically isolated and lymphocyte suspensions were prepared. Antigen-specific B lymphocytes were enriched using flow cytometry and immortalized to obtain monoclonal cell lines that could stably secrete target antibodies.

[0030] 3. Screening and pairing of monoclonal antibodies The supernatant of monoclonal cell lines was screened using an indirect ELISA method to identify monoclonal antibodies that specifically bind to PTH and do not cross-react. After multiple rounds of screening, two monoclonal antibodies with high specificity and affinity, AB1 and AB2, were obtained. AB1 is suitable as a capture antibody immobilized on the detection line, while AB2 is suitable as a detection antibody labeled with colloidal gold particles.

[0031] 4. Antibody sequence and epitope analysis Sequence determination of AB1 and AB2 showed the following results: Capture antibody AB1 Complete sequence of heavy chain variable region (VH): QVQLQESGPGLVKPSETLSLTCTVSGGTITAKAYYWSWIRQPPGKGLEWIGYIYYSGSTYYNPSLKSRVTISSVDTSKNQFSLKLSSVTAADTAVYYCAREGHYYGSSHWYFDVWGQGTLVTV (SEQ ID NO.1) CDR-H1: GGTITAKAYY(SEQ ID NO.2) CDR-H2: IYYSGST (SEQ ID NO.3) CDR-H3: EGHYYGSSHWYF (SEQ ID NO.4) Complete sequence of light chain variable region (VL): DIQMTQSPSSSLSASVGDRVTITCRASQDVSIAVAWYQQKPGKAPKLLIYSASYRYTGVPDRFTGSGSGTDFTLTISSLQPEDFATYYCQQYYSTPLTFGAGTKLELK (SEQ ID NO.5) CDR-L1: ASQDVSIA (SEQ ID NO.6) CDR-L2: ASYRYT(SEQ ID NO.7) CDR-L3: QQYYSTPLT (SEQ ID NO.8) Detection of antibody AB2 Complete sequence of heavy chain variable region (VH): EVKLVESGGDLVKPGGSLKLSCAASGFTFDDYAISWVRQAPGKGLEWVSTISYDGSNKYYADSVKGRFTISRDNAKNTLYLQMNSLKPEDTAVYYCSRWGGYFGYWGQVTA (SEQ ID NO.9) CDR-H1: GFTFDDYA (SEQ ID NO.10) CDR-H2: ISYDGSNKY (SEQ ID NO.11) CDR-H3: SRWGGYFGY (SEQ ID NO.12) Complete sequence of light chain variable region (VL): SYELTQPPSVSVAPGQTARITCTGDKLGDKYASWYQQKPGQAPVLVVYDDNQRPSGIPERFSGNSGNTATTLTISRVEAGDEADYYCQSYDNSNLVFGGGTK (SEQ ID NO.13) CDR-L1: KLGDKYA (SEQ ID NO.14) CDR-L2: YDDNQRP (SEQ ID NO.15) CDR-L3: QSYDNSNLV (SEQ ID NO.16) 5. Large-scale antibody production Positive monoclonal cell lines were subjected to large-scale in vitro serum-free suspension culture and purified using Protein A / G affinity chromatography to obtain high-purity rabbit-derived monoclonal antibodies AB1 and AB2, which were used for subsequent test strip preparation.

[0032] Example 2: Preparation of a colloidal gold test strip for parathyroid gland detection 1. Preparation of test strip assembly Base plate: Made of PVC board to ensure the stability of the test strip structure; Sample pad: Take a glass fiber membrane, soak it in phosphate buffer containing 3% BSA and 0.5% Tween-20, soak it at room temperature for 2 hours, and then dry it in an oven at 37°C for 12 hours to obtain a sample pad, which is used to optimize sample flow rate and reduce non-specific adsorption. Filter membrane: Select a cellulose filter membrane with a pore size of 5μm, cut it for later use, and use it to separate tissue debris and blood cells; Colloidal gold conjugate pad: ① A colloidal gold solution was prepared using the trisodium citrate reduction method, and the pH was adjusted to 8.0; ② The purified detection antibody AB2 was covalently coupled to colloidal gold particles, labeled, washed, and resuspended in a storage solution; ③ The AB2-colloidal gold complex was quantitatively sprayed onto a glass fiber membrane at a rate of 1 μL / cm and dried at 37℃ for 6 hours to obtain the colloidal gold conjugate pad; Test pad: ① Immerse the nitrocellulose membrane in blocking solution (0.01M PBS containing 1% BSA, 0.1% Tween-20, pH 7.0) for 60 minutes and dry at 37℃; ② Using a spotting apparatus, spray the capture antibody AB1 (2.5μg / mL) and goat anti-rabbit IgG (1.5μg / mL) onto the membrane at a linear velocity of 2μL / cm to form a test line (T line) and a control line (C line) spaced 5mm apart. The spotting dilution solution is 0.01M PBS (pH 7.4) containing 0.15M NaCl, 10mM EDTA, 1g / L NaN3 and 25g / L methanol; ③ After spraying, dry at 37℃ for 12 hours to obtain the nitrocellulose membrane; Absorbent pad: An absorbent cotton pad is used to ensure rapid adsorption of the chromatography solvent.

[0033] 2. Test strip assembly The sample pad, filter membrane, colloidal gold binding pad, nitrocellulose membrane, and absorbent pad prepared above are stacked sequentially on a PVC base plate to ensure smooth flow of the chromatography solvent. After assembly, the sample pad is cut into test strips using a cutting machine. The test strips are placed upright in the card holder, and the card holder is pressed and sealed to obtain a test card with a protective shell. The card is then sealed and stored in a packaging bag containing desiccant.

[0034] Example 3 Antibody efficacy verification experiment Enzyme-linked immunosorbent assay (ELISA) was used to verify the specificity and sensitivity of antibodies against AB1 and AB2 for PTH: 1. Coating: Dilute the capture antibody AB1 with PBS buffer to 2 μg / mL, add 50 μL to each well of a 96-well microplate, and incubate overnight at 4°C; 2. Washing: Discard the coating solution and wash three times with PBS buffer, 5 minutes each time; 3. Blocking: Add 150 μL of PBS solution containing 3% BSA to each well, incubate at 37°C for 1.5 hours, and wash 3 times; 4. Sample addition: Add 50, 250, 500, 1000, 1500, or 3000 pg / mL of human PTH standard to each well, incubate at 37°C for 1 hour, and wash 3 times; 5. Detection: Add horseradish peroxidase (HRP)-labeled detection antibody AB2, incubate at 37°C for 1 hour, and wash 3 times; 6. Color development and reading: Add color development solution, incubate at room temperature in the dark for 15 minutes, add stop solution, and read the absorbance value using an ELISA reader.

[0035] The antibody pair exhibits a good dose-response relationship in the concentration range of 50-3000 pg / mL, with a linear correlation coefficient R²>0.998, indicating that the antibody pair has high sensitivity and high specificity and is suitable for the quantitative detection of PTH.

[0036] Example 4: Performance Testing of Colloidal Gold Test Strips 1. Sensitivity and Linear Range Test Take an accurate quantitative amount of 50,000 pg / mL of exudate from parathyroid gland reimplantation tissue, and serially dilute it to the original solution (1×), 1:10, 1:100, 1:1000, and 1:10000. Set up a negative control (physiological saline). Take 50 μL of each sample and add it to the sample pad of the test strip. Incubate at room temperature for 15 minutes and observe the color development of the test line and control line.

[0037] Within a concentration range of 50,000 pg / mL (1×) to 500 pg / mL (1:100), the color depth of the test line showed a good linear correlation with the PTH concentration. The lowest detectable concentration was 500 pg / mL, which is much higher than the PTH concentration in blood (15-65 pg / mL), and the positive detection rate was 100% after 10 repeated tests at this concentration. Blood samples and other tissue exudate specimens all showed negative results, indicating that the test strip has high sensitivity and stability.

[0038] 2. Actual detection method for parathyroid gland tissue For qualitative testing, add 50 μL of the suspected tissue exudate or the supernatant of the tissue suspension to be re-implanted to the sample application area of ​​the test strip and perform chromatography at 20-30℃ for 5 min. The presence of parathyroid glands can be determined by observing the test line and control line. Specifically, when both the test line and control line show color, the sample contains a high concentration of PTH, indicating that the suspected tissue is parathyroid glands; when the test line does not show color but the control line does, the sample does not contain a high concentration of PTH, indicating that the suspected tissue is another type of tissue.

[0039] When used with a quantitative scanning device, this test strip can be used to quantitatively detect the PTH concentration in a sample. After the chromatographic reaction, the test strip is placed under the scanning device for scanning. The grayscale value of the scanned image is compared with the standard curve of the corresponding batch of test strips to obtain the PTH concentration.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A colloidal gold test strip for detecting human parathyroid hormone, characterized in that, The colloidal gold test strip contains at least a capture antibody and a detection antibody; The amino acid sequences of the heavy chain variable regions CDR-H1, CDR-H2, and CDR-H3 of the capture antibody AB1 are shown in SEQ ID NO. 2-4, respectively; and the amino acid sequences of the light chain variable regions CDR-L1, CDR-L2, and CDR-L3 are shown in SEQ ID NO. 6-8, respectively. The amino acid sequences of the heavy chain variable regions CDR-H1, CDR-H2 and CDR-H3 of the detection antibody AB2 are shown in SEQ ID NO.10-12, respectively; and the amino acid sequences of the light chain variable regions CDR-L1, CDR-L2 and CDR-L3 are shown in SEQ ID NO.14-16, respectively.

2. The colloidal gold test strip as described in claim 1, characterized in that, The amino acid sequence of the heavy chain variable region of the capture antibody AB1 is shown in SEQ ID NO.1; the amino acid sequence of the light chain variable region of the capture antibody AB1 is shown in SEQ ID NO.

5.

3. The colloidal gold test strip as described in claim 1, characterized in that, The amino acid sequence of the heavy chain variable region of the detection antibody AB2 is shown in SEQ ID NO. 9; the amino acid sequence of the light chain variable region of the detection antibody AB2 is shown in SEQ ID NO.

13.

4. The colloidal gold test strip according to any one of claims 1-3, characterized in that, The colloidal gold test strip includes: a base plate, on which a sample pad, a colloidal gold binding pad, a detection pad and an absorbent pad are sequentially arranged, with adjacent pads overlapping and connected at the joint.

5. The colloidal gold test strip as described in claim 4, characterized in that, The base plate is made of cardboard or PVC board.

6. The colloidal gold test strip as described in claim 4, characterized in that, The sample pad is a glass fiber membrane that has been soaked in a treatment solution, which is a phosphate buffer containing 1-5% BSA and a surfactant; further, the surfactant is Tween-20 with a concentration of 0.1-1%.

7. The colloidal gold test strip as described in claim 4, characterized in that, The colloidal gold conjugate pad uses a glass fiber membrane as the base pad, on which the colloidal gold-conjugated detection antibody AB2 is coated. The detection pad uses a nitrocellulose membrane as a base, and a control line and a detection line are sequentially arranged on the nitrocellulose membrane. The detection line is coated with capture antibody AB1, and the control line is coated with goat anti-rabbit IgG. The absorbent pad is either an absorbent board or an absorbent cotton pad.

8. The colloidal gold test strip as described in claim 4, characterized in that, A filter membrane is placed at the interface between the sample pad and the colloidal gold binding pad.

9. A reagent kit, characterized in that, The kit comprises at least the colloidal gold test strip for detecting human parathyroid hormone as described in any one of claims 1-8; further, the colloidal gold test strip in the kit also has a shell.

10. The use of the colloidal gold test strip according to any one of claims 1-9 or the kit according to claim 9 in any one or more of the following: (a) Detecting parathyroid hormone or preparing products for detecting parathyroid hormone; (b) Identify parathyroid tissue or prepare a product that identifies parathyroid tissue.

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