title: The development of a direct homologous radioimmunoassay for serum cortisol.
abstract: This article describes the synthesis of a pure cortisol-3-(O-carboxymethyl) oxime with its subsequent use in producing highly specific antibodies and a 125I-tracer with a shelf life in excess of several weeks. An assay was developed using a pH of 4, thus allowing a direct measurement of cortisol in serum without extraction or heat denaturation. The quality-control parameters were checked - the intra-assay C.V. in the working range (area of clinical interest) was under 5%, and the interassay C.V. under 11%. Correlation studies with results using other antisera and with 3H-tracer are highly significant with the slope of the regression curve deviating less than 2% from the ideal volume. Finally the assay is fully automatable and is suitable for most automatic pipetting and analysis systems.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000918:Antibody Specificity; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007457:Iodine Radioisotopes; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D007457:Iodine Radioisotopes; D006854:Hydrocortisone