Enzyme immunoassay with high sensitivity and accuracy for specific antibody to neocarzinostatin

A quantitative enzyme immunoassay (EIA) for specific antibody to neocarzinostatin (NCS) is described which uses enzyme-labeled anti-rabbit IgG antibody, solid-phase NCS and standard purified specific antibody to NCS. The dose of the standard was determined by sandwich EIA for rabbit IgG. The lower detection limit was 3 ng of the specific antibody per tube. The accuracy of the assay was excellent and a comparative study with the sandwich EIA for rabbit IgG showed good correlation. The antiserum to NCS of the highest titer was found to contain 0.6 mg and 40 mg per ml of specific antibody to NCS and of normal IgG, respectively. The accuracy of the assay results and the purity of the standard was established by 2 recovery tests for anti-NCS antibody.