Hybridoma cell strain secreting anti-captopril monoclonal antibody and application thereof

Abstract

The invention relates to a hybridoma cell strain secreting an anti-captopril monoclonal antibody and application of the hybridoma cell strain, and belongs to the technical field of drug safety immunoassay. The hybridoma cell strain secreting the anti-monoclonal antibody is preserved in China General Microbiological Culture Collection Center (CGMCC) on the year, the preservation number is CGMCC No.46502, the preservation address is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the hybridoma cell strain is classified and named as a monoclonal cell strain. The captopril monoclonal antibody cell strain obtained by the invention can be used for drug quality detection and captopril residue detection in a biological sample, has better detection sensitivity (IC50 value is 3.433 ng / mL) and specificity (the cross-over rate for related structural analogues is less than 1%) to captopril, and can realize detection of captopril in drugs and biological samples; and an efficient immunodetection tool is provided for clinical medication detection and drug quality control, the clinical medication safety and effectiveness are guaranteed in an assisted manner, and the kit has a definite practical application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of drug safety immunological detection technology, in particular to a hybridoma cell strain secreting anti-captopril monoclonal antibody and its application. BACKGROUND

[0002] Captopril is an angiotensin-converting enzyme inhibitor (ACEI) mainly used for treating hypertension, congestive heart failure, diabetic nephropathy and other cardiovascular and related diseases. Its mechanism of action is to inhibit the activity of angiotensin-converting enzyme, thereby dilating blood vessels, reducing blood pressure, and reducing the load on the heart and protecting kidney function.

[0003] However, the safety of captopril has been controversial. Studies have shown that long-term excessive intake of captopril may pose potential health risks, such as interfering with the endocrine system in the human body, increasing the likelihood of certain tumors, and having a more significant impact on the health of children and sensitive populations. In addition, some companies have violated regulations by using excessive amounts in pursuit of product preservation effects, leading to frequent problems of excessive captopril residues in food and drugs.

[0004] In clinical diagnosis and treatment, it is crucial to accurately grasp the concentration changes of captopril in the body. Currently, the main methods for determining the content of captopril include ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS / MS), gas chromatography-tandem mass spectrometry (GC-MS / MS), and high-performance liquid chromatography (HPLC-UV). However, these methods have obvious limitations, as they require professional equipment and operators, and the detection cost is relatively high, making it difficult to meet the needs of clinical instant monitoring and batch sample detection.

[0005] The enzyme-linked immunosorbent assay (ELISA) technology provides a new solution for captopril detection. This technology, with its high sensitivity and fast detection speed, can achieve trace detection of captopril in biological samples such as blood and urine, and is relatively simple to operate, greatly improving the flexibility and timeliness of detection. The application of this technology is expected to solve the problems of traditional detection methods and promote the development of captopril clinical detection technology, providing more efficient technical support for precise medication guidance and ensuring patient medication safety. SUMMARY

[0006] To solve the deficiencies of existing technology in captopril detection by instruments, the present application provides a hybridoma cell strain secreting anti-captopril monoclonal antibody and its application. The antibody secreted by the cell strain has high detection sensitivity for captopril and can be used to establish an immunological detection method for captopril.

[0007] The present application is achieved by the following technical solutions:

[0008] The first object of the present application is to provide a hybridoma cell strain secreting anti-captopril monoclonal antibody, which has been preserved in the China General Microbiological Culture Collection Center on April 17, 2025, with a preservation number of CGMCC No. 46502, a preservation address of No. 3, Beichen West Road, Chaoyang District, Beijing, and a classification name of monoclonal cell strain.

[0009] In an embodiment of the present application, the hybridoma cell strain is obtained by immunizing a mouse with a captopril complete antigen.

[0010] In an embodiment of the present application, the captopril complete antigen is obtained by coupling the captopril hapten with a carrier protein.

[0011] In an embodiment of the present application, the immunogenic carrier is selected from keyhole limpet hemocyanin and / or chicken egg white protein.

[0012] In an embodiment of the present application, the structure of the captopril hapten is:

[0013]

[0014] The second object of the present application is to provide a captopril monoclonal antibody, which is secreted by the hybridoma cell strain.

[0015] In an embodiment of the present application, sterile paraffin oil is injected into the abdominal cavity of an immunized animal, and then the hybridoma cell strain with a preservation number of CGMCC No. 46502 is injected into the abdominal cavity. After injection, ascites is collected, purified, and stored at low temperature to obtain the captopril monoclonal antibody.

[0016] The third object of the present application is to provide a composition for detecting captopril, which comprises the hybridoma cell strain and / or the captopril monoclonal antibody.

[0017] The fourth object of the present application is to provide a kit for detecting captopril, which comprises one or more of the hybridoma cell strain, the captopril monoclonal antibody, and the composition.

[0018] In an embodiment of the present application, the kit is selected from an enzyme-linked immunoassay kit, a fluorescent immunoassay kit, or a chemiluminescent immunoassay kit.

[0019] The fifth object of the present application is to provide a test strip for detecting captopril, which comprises one or more of the hybridoma cell strain, the captopril monoclonal antibody, and the composition.

[0020] The sixth object of the present application is to provide the use of the hybridoma cell strain, the monoclonal antibody against captopril, the composition, the kit or the test strip in detecting captopril, especially in analyzing and detecting the residual captopril in drugs and biological samples.

[0021] The seventh object of the present application is to provide a method for preparing the hybridoma cell strain secreting the monoclonal antibody against captopril, comprising the following steps,

[0022] S1, preparing a captopril hapten;

[0023] S2, preparing a captopril immunogen and a captopril coating antigen, and preparing the obtained captopril immunogen into a complete Freund's adjuvant containing antigen and an incomplete Freund's adjuvant containing antigen;

[0024] S3, performing a first immunization, a booster immunization and a boost immunization on the immunized animal, wherein the first immunization adopts the complete Freund's adjuvant containing antigen in S2, the booster immunization adopts the incomplete Freund's adjuvant containing antigen in S2, and the boost immunization adopts the captopril immunogen in S2;

[0025] S4, obtaining the hybridoma cell strain secreting the monoclonal antibody against captopril by fusing the spleen cells of the immunized animal after the boost immunization in S3 with myeloma cells.

[0026] In an embodiment of the present application, in step S1, the method for preparing the captopril hapten comprises the following steps: dissolving syringyl hydroxyanisole and ethyl bromohexanoate in a solvent, adding potassium carbonate, heating in a water bath, removing the organic solvent, washing, drying, and obtaining a yellow oil. Subsequently, the yellow oil is dissolved in methanol, and sodium hydroxide solution is added, and then heated in a water bath, washed, recrystallized, and the captopril hapten is obtained.

[0027] In an embodiment of the present application, in step S2, the method for preparing the captopril immunogen and the coating antigen comprises the following steps: coupling the captopril hapten with carrier proteins KLH and OVA respectively to prepare the immunogen captopril-KLH and the coating antigen captopril-OVA by using the carbodiimide method.

[0028] In an embodiment of the present application, the method for preparing the captopril immunogen and the coating antigen specifically comprises the following steps: dissolving the captopril hapten in DMF, adding N-hydroxysuccinimide and 1-ethyl carbodiimide hydrochloride, stirring and reacting at room temperature to obtain solution A; weighing different carrier proteins and adding a buffer solution to obtain solution B; slowly adding solution A drop by drop into solution B under stirring, and reacting at room temperature to obtain a mixed solution; dialyzing to obtain the captopril immunogen and the coating antigen.

[0029] In one embodiment of the present application, in step S2, the antigen-containing Freund's complete adjuvant is an emulsion of equal volume of Freund's complete adjuvant mixed with the captopril immunogen.

[0030] In one embodiment of the present application, in S2, the antigen-containing Freund's incomplete adjuvant is an emulsion of equal volume of Freund's incomplete adjuvant mixed with the captopril immunogen.

[0031] In one embodiment of the present application, in step S3, the entire immunization process includes one primary immunization, 3-5 booster immunizations, and one boost immunization.

[0032] In one embodiment of the present application, in step S3, the entire immunization process includes one primary immunization, 3-5 booster immunizations, and one boost immunization.

[0033] In one embodiment of the present application, in step S3, the primary immunization and the booster immunization are performed by subcutaneous injection on the back of the immunized animal, and the boost immunization is performed by intraperitoneal injection.

[0034] In one embodiment of the present application, in step S3, during the booster immunization, blood is collected from the immunized animal, and the serum titer and inhibition rate are detected by indirect competitive enzyme-linked immunosorbent assay (icELISA) to screen out immunized animals with high titer and good inhibition.

[0035] In one embodiment of the present application, in step S3, blood is collected 6-8 days after the end of the booster immunization.

[0036] In one embodiment of the present application, in step S4, cell fusion is performed by culturing the fused cells in RPMI-1640 screening medium containing fetal bovine serum and 50xHAT, detecting positive cell wells by indirect ELISA, further determining the inhibition effect of the positive cell wells by indirect competitive ELISA, subcloning the positive cell wells with the best inhibition by limiting dilution method, and obtaining a hybridoma cell strain.

[0037] In one embodiment of the present application, the subcloning is performed 2-3 times.

[0038] In one embodiment of the present application, in step S4, the cell fusion is performed by polyethylene glycol (PEG 1500) method.

[0039] In one embodiment of the present application, in step S4, the cell fusion is performed 3 days after the end of the boost immunization.

[0040] The technical solution of the present application has the following advantages compared with the prior art:

[0041] The monoclonal antibody secreted by the hybridoma cell strain provided by the present application has good specificity (crossing rate of less than 1% to related structural analogues) and detection sensitivity (IC 50 The values are 3.433 ng / mL, respectively, which can realize the detection of the content of captopril in biological samples. With the above characteristics, the monoclonal antibody can realize high-precision detection of the content of captopril in drugs and biological samples, provide an efficient immunodetection tool for clinical drug detection and drug quality control, help to ensure the safety and effectiveness of clinical drug use, and has clear practical application value.

[0042] Biological material preservation:

[0043] A hybridoma cell strain LXP secreting captopril monoclonal antibody has been preserved in the China General Microbiological Culture Collection Center (CGMCC), located at No. 1, Beichen West Road, Haidian District, Beijing, China, Institute of Microbiology, Chinese Academy of Sciences, classified as a monoclonal cell strain, preserved on April 17, 2025, and preserved under the number CGMCC No. 46502. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, in which:

[0045] Figure 1 The standard curve of the captopril monoclonal antibody of the present application for inhibiting captopril. DETAILED DESCRIPTION

[0046] The present application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting the present application.

[0047] The experimental methods used in the following examples are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0048] (1) The culture medium involved in the following examples is as follows:

[0049] RPMI-1640 medium (mg / L): L-arginine 290, L-asparagine 50, L-aspartic acid 20, L-cystine dihydrochloride 65.15, L-glutamic acid 20, glycine 10, L-histidine 15, L-hydroxyproline 20, L-isoleucine 50, L-leucine 50, L-lysine hydrochloride 40, L-methionine 15, L-phenylalanine 15, L-proline 20, L-serine 30, L-threonine 20, L-tryptophan 5, L-tyrosine 23.19, L-valine 20, p-aminobenzoic acid 1, calcium nitrate 100, magnesium sulfate anhydrous 48.84, sodium phosphate monobasic anhydrous 676.13, potassium chloride 400, sodium chloride 6000, glucose 2000, reduced glutathione 1, phenol red 5, L-glutamine 300, biotin 0.2, calcium D-pantothenate 0.25, folic acid 1, i-inositol 35, nicotinamide 1, choline chloride 3, pyridoxine hydrochloride 1, riboflavin 0.2, thiamine hydrochloride 1, vitamin B12 0.005, sodium bicarbonate 2000.

[0050] (2) The reagents involved in the following examples are as follows:

[0051] Carbonate buffer solution (CBS): weigh 1.59 g of Na2CO3 and 2.93 g of NaHCO3, respectively, dissolve in a small amount of double distilled water, mix, add double distilled water to about 800 mL, mix well, adjust the pH value to 9.6, add double distilled water to 1000 mL, store at 4°C for standby;

[0052] Phosphate buffer solution (PBS): 8.00 g of NaCl, 0.2 g of KCl, 0.2 g of KH2PO4, 2.9 g of Na2HPO4·12H2O, dissolved in 800 mL of pure water, adjusted to pH 7.2-7.4 with NaOH or HCl, and diluted to 1000 mL with ultrapure water;

[0053] Washing solution (PBST): 1000 mL of 0.01 mol / L PBS solution with pH 7.4, add 0.5 mL of Tween-20;

[0054] Antibody diluent: washing solution containing 0.1% gelatin;

[0055] TMB developing solution: A solution: 18.43 g of Na2HPO4·12H2O, 9.33 g of citric acid, and pure water to 1000 mL; B solution: 60 mg of TMB dissolved in 100 mL of ethylene glycol. Mix A and B solutions in a volume ratio of 5:1 to obtain TMB developing solution, mix fresh as needed.

[0056] (3) The detection methods involved in the following examples are as follows:

[0057] Captopril inhibition rate detection method: The most suitable antigen and antibody concentration in icELISA was selected by chessboard test. The antigen was diluted to 1 μg / mL, 0.3 μg / mL, 0.1 μg / mL and 0.03 μg / mL with carbonate buffer solution (CBS), and the antibody was diluted to 1 μg / mL, 0.3 μg / mL, 0.1 μg / mL and 0.03 μg / mL with antibody diluent. After selecting the optimal working point, the captopril standard was diluted to 100 ng / mL, 33.33 ng / mL, 11.11 ng / mL, 3.70 ng / mL, 1.23 ng / mL, 0.41 ng / mL and 0.14 ng / mL, etc. According to the icELISA operation steps, the final graph was drawn by Origin 2024, and the captopril standard inhibition curve was obtained to calculate the IC 50 .

[0058] Embodiment:

[0059] The present embodiment provides a preparation method of a hybridoma cell strain secreting anti-captopril monoclonal antibody, which specifically comprises the following steps:

[0060] (1) Preparation of hapten

[0061] 100 mg syringyl hydroxyanisole was dissolved in a solvent, and after stirring uniformly, 212.3 mg EDC was added, and the reaction was stirred at 80°C for 1 h. After cooling, 228.3 mg of amino hexanoic acid ethyl ester hydrochloride dissolved in a solvent was added, and the reaction was carried out at room temperature for 24 h. Then, the mixture was washed with deionized water and dried to obtain a yellow oil. Subsequently, the yellow oil was added to methanol and 1M NaOH, heated in a 70°C water bath for 43 h, and the organic solvent was removed. The mixture was washed with deionized water and 1M HCl three times, and then recrystallized by adding ethanol to obtain a white solid, which was captopril hapten Cap-COOH.

[0062] (2) Preparation of immunogen

[0063] 7.8 mg of captopril hapten Cap-COOH was weighed and dissolved in 300 μL of DMF. After stirring at room temperature for 15 min, 13.2 mg of 1-ethylcarbodiimide hydrochloride was added, and the reaction was carried out at room temperature for 6 h. The obtained mixture was named as A liquid. Then, 6 mg of keyhole limpet hemocyanin (KLH) was dissolved in 2 mL of carbonate buffer solution, and was named as B liquid. A liquid was slowly added to B liquid, and the reaction was carried out at room temperature for 24 h under stirring. The coupling product Cap-COOH-KLH was obtained by dialysis with 0.01 mol / L phosphate buffer PBS for 3 days, and was stored at -20°C for standby.

[0064] (3) Preparation of coating antigen

[0065] Take 5.9 mg of captopril hapten Cap-COOH, dissolve in 300 μL of DMF, add 6.2 mg of N-hydroxysuccinimide under stirring at room temperature, react for 15 min, then add 8.9 mg of 1-ethylcarbodiimide hydrochloride, react for 6 h at room temperature, and the obtained mixture is referred to as A liquid; then take 10 mg of chicken egg white protein (OVA) and dissolve in 2 mL of carbonate buffer, referred to as B liquid; slowly drop A liquid into B liquid, react for 24 h at room temperature under stirring, and then dialyze against 0.01 mol / L PBS for 3 days, to obtain the conjugate Cap-COOH-OVA, which is stored at -20℃ for later use;

[0066] (4) Immunization of mice: healthy 6-8 week old BALB / c mice were selected for immunization. The captopril immunogen was mixed with an equal amount of Freund's adjuvant and emulsified, and then subcutaneously injected into the back of BALB / c mice. Complete Freund's adjuvant was used for the first immunization, and incomplete Freund's adjuvant was used thereafter. The interval between the first immunization and the second boosting immunization was 28 days, and the interval between multiple boosting immunizations was 21 days. Blood was collected 7 days after the third immunization (5 μL of mouse tail blood + 995 μL of antibody diluent = antiserum), and the mouse serum titer and inhibition were determined using icELISA. Mice with high titer and good inhibition were selected, and then subjected to a booster immunization 21 days after the fifth immunization, and injected intraperitoneally. The booster immunization dose was required to be halved and free of any adjuvant.

[0067] (5) Cell fusion: three days after the booster immunization, cell fusion was performed according to the conventional PEG (polyethylene glycol, molecular weight 1500) method, and the specific steps were as follows:

[0068] a. After the mice were sacrificed by cervical dislocation with the aid of carbon dioxide, the eyeballs were immediately disinfected in 75% alcohol for about 5 min, and the spleen was removed under sterile conditions. The spleen was gently ground with a syringe rubber head and passed through a 200-mesh cell sieve to obtain a spleen cell suspension. The suspension was collected and centrifuged (1200 rpm, 8 min). The spleen cells were washed three times with RPMI-1640 medium, and then diluted to a certain volume after the last centrifugation. The number of cells was counted and reserved for later use;

[0069] b. Collection of mouse myeloma SP2 / 0 cells: 7-10 days before fusion, the SP2 / 0 tumor cells were cultured in RPMI-1640 medium containing 10% FBS (fetal bovine serum) in a 5% CO2 incubator. The number of SP2 / 0 tumor cells was required to reach (1-4) × 10 7 before fusion to ensure that the SP2 / 0 tumor cells were in the logarithmic growth phase. Before fusion, the tumor cells were collected and suspended in RPMI-1640 basic culture medium (RPMI-1640 medium) for cell counting;

[0070] c. Fusion process 7 min. At 1 min, 1 mL of PEG 1500 was added to the cells from slow to fast; at 2 min, stand. At 3 min and 4 min, 1 mL of RPMI-1640 medium was added within 1 min; at 5 min and 6 min, 2 mL of RPMI-1640 medium was added within 1 min; at 7 min, 1 mL of RPMI-1640 medium was added every 10 seconds. Then 37°C water bath for 5-8 min. Centrifugation (800 rpm, 8 min), discard the supernatant, resuspended in RPMI-1640 screening medium (containing 20% fetal bovine serum, 2% of 50xHAT RPMI-1640 medium), according to 200 μL / well to 96-well cell plate, placed in 37°C, 5% CO2 incubator for culture.

[0071] (6) Cell screening and cell strain establishment: On the 3rd day of cell fusion, the fusion cells were semi-replaced with RPMI-1640 screening medium (containing 20% fetal bovine serum, 2% of 50xHAT RPMI-1640 medium), on the 5th day, full replacement was performed with RPMI-1640 transition medium (containing 20% fetal bovine serum, 1% of 100xHT RPMI-1640 medium), and on the 7th day, the cell supernatant was taken for screening. Screening was divided into two steps: first, positive cell wells were screened by icELISA, and second, the inhibitory effect of positive cells was determined by icELISA using captopril as a standard. Cell wells with good inhibition to captopril standard were selected, and subcloning was performed by limiting dilution, and the same method was used for detection, repeated three times, to obtain cell strains.

[0072] Test example:

[0073] (1) Preparation and identification of monoclonal antibody

[0074] Take 6-8 weeks old BALB / c mice, each mouse was injected with 0.5 mL of sterile paraffin oil into the abdominal cavity; 7 days later, each mouse was injected with 1x10 6 Hybridoma cells, starting from the 7th day, the ascites was collected, and the ascites was purified by caprylic acid-ammonium sulfate method. In the slightly acidic condition, n-octanoic acid can precipitate other impurities in the ascites except IgG immunoglobulin, then centrifugation, discard the precipitate; then precipitate IgG type monoclonal antibody with equal saturation of ammonium sulfate solution, centrifugation, discard the supernatant, dissolve with 0.01M PBS solution (pH 7.4), dialysis and desalination, finally obtain the purified monoclonal antibody stored at -20°C.

[0075] Using indirect competitive ELISA method, the IC 50 of the monoclonal antibody to captopril was determined, and the IC 50and cross-reactivity, the cross-reactivity of the monoclonal antibody to Captopril was less than 1%, wherein the cross-reactivity = (IC50 of Captopril / IC50 of the analogue) x 100%, according to the cross-reactivity value, it can be seen that the antibody has high sensitivity and specificity to Captopril, as shown in Table 1: 50 / analogue 50 Table 1 shows the IC50 and cross-reactivity of the monoclonal antibody to Captopril, functional analogue Benazepril, Fosinopril and Ranopril:

[0076] Table 1 shows the IC50 and cross-reactivity of the monoclonal antibody to Captopril, functional analogue Benazepril, Fosinopril and Ranopril: 50 and cross-reactivity

[0077] Table 1 shows the IC50 and cross-reactivity of the monoclonal antibody to Captopril, functional analogue Benazepril, Fosinopril and Ranopril:

[0078] IC 50 (ng / mL) Cross-reactivity (%) Captopril 3.433 100 Benazepril >34.3 <1 Fosinopril >34.3 <1 Ranopril >34.3 <1

[0079] (2) Antibody application

[0080] The monoclonal antibody prepared by the hybridoma cell line through in vivo ascites was applied to the addition recovery test of Captopril, and the specific steps were as follows:

[0081] a. Coating: the coating original Captopril-OVA was diluted by 100 μL / well at 37°C for 2 h, starting from 1 μg / mL with 0.05M pH 9.6 carbonate buffer;

[0082] b. Washing: the solution in the plate was poured off, and washed with washing solution for 3 times, each time for 3 min;

[0083] c. Blocking: after drying, 200 μL / well of blocking solution was added, and reacted at 37°C for 2 h. After washing, it was dried for standby;

[0084] d. Sample addition: the antiserum (after tail blood collection of mice, the corresponding multiple of the antibody diluent was diluted to be the antiserum) was diluted by 100 μL / well at 37°C for 30 min, starting from 1:1000, and added to each dilution coated well, 100 μL / well, 37°C for 30 min; after washing, 1:3000 diluted HRP-goat anti-mouse IgG was added, 100 μL / well, 37°C for 30 min;

[0085] e. Color development: the enzyme-labeled plate was taken out, washed thoroughly, and 100 μL of TMB color developing liquid was added to each well, 37°C for 15 min in the dark;

[0086] f. Termination and determination: 50 μL of termination liquid was added to each well to terminate the reaction, and then the OD 450 value of each well was determined by an enzyme-labeled instrument.

[0087] The inhibition standard curve of the Captopril monoclonal antibody to Captopril is shown in Figure 1 , and the IC50 of the monoclonal antibody to Captopril was determined by icELISA: 50The sensitivity to Captopril is 3.433 ng / mL, which indicates that the monoclonal antibody has good sensitivity to Captopril and can be used for the immunoassay detection of Captopril.

[0088] For the recovery rate, the biological samples were detected by liquid chromatography tandem mass spectrometry (LC-MS / MS), and the Captopril residues in the two samples were not detected by LC-MS / MS detection. Therefore, the recovery rate was determined by adding Captopril. As shown in Table 2, the results of indirect competitive ELISA and LC-MS / MS are similar, which indicates that the method for detecting Captopril based on the monoclonal antibody of Captopril is accurate and can be used for the immunoassay detection of Captopril residues in blood and urine and other biological samples.

[0089] Table 2 shows the recovery rate of monoclonal antibody to blood and urine in indirect competitive ELISA and LC-MS / MS of Captopril

[0090]

[0091] Obviously, the above examples are only examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A hybridoma cell line that secretes an anti-captopril monoclonal antibody, characterized in that, The hybridoma cell line was deposited on April 17, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 46502. The deposit address is No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, and it is classified as a monoclonal cell line.

2. The hybridoma cell line according to claim 1, characterized in that, The hybridoma cell line was obtained by immunizing mice with captopril complete antigen.

3. The hybridoma cell line according to claim 2, characterized in that, The captopril complete antigen is obtained by conjugating the captopril hapten with a carrier protein.

4. The hybridoma cell line according to claim 3, characterized in that, The structural formula of the captopril hapten is:

5. Captopril monoclonal antibody, characterized in that, Produced by the hybridoma cell line according to any one of claims 1-4.

6. A composition for detecting captopril, characterized in that, The composition comprises the hybridoma cell line of any one of claims 1-4 and / or the captopril monoclonal antibody of claim 5.

7. A kit for detecting captopril, characterized in that, The kit comprises one or more of the hybridoma cell lines of any one of claims 1-4, the captopril monoclonal antibody of claim 5, and the composition of claim 6.

8. The reagent kit according to claim 7, characterized in that, The kit is selected from enzyme-linked immunosorbent assay (ELISA) kits, fluorescence immunoassay kits, or chemiluminescence immunoassay kits.

9. A test strip for detecting captopril, characterized in that, The test strip comprises one or more of the hybridoma cell lines of any one of claims 1-4, the captopril monoclonal antibody of claim 5, and the composition of claim 6.

10. The use of the hybridoma cell line of any one of claims 1-4, the captopril monoclonal antibody of claim 5, the composition of claim 6, the kit of claim 7 or 8, or the test strip of claim 9 in the detection of captopril.

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