title: A radioimmunoassay for total captopril in human serum or plasma samples.
abstract: A radioimmunoassay for the measurement of total captopril in serum and heparinized plasma has been developed. Prior to the assay, serum or heparinized plasma samples are subjected to tri-n-butyl-phosphine reduction followed by N-ethylmaleimide (NEM) derivatization. The assay utilizes in-house NEM-captopril antibody, [125I]NEM-captopril radiolabel and human serum standards. Satisfactory zero binding and sensitivity are obtained after 3 h of incubation at room temperature. Separation of the antibody-bound and free radiolabeled antigen is achieved by employing a polyethylene glycol solution. The assay was shown to have excellent parallelism, recovery, and precision. Cross-reactivities with potentially interfering substances were low.
mesh_terms: D002216:Captopril / Q000097:blood*; D006801:Humans; D010949:Plasma / Q000032:analysis*; D011392:Proline / Q000031:analogs & derivatives*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D011392:Proline; D002216:Captopril