Improved radioimmunoassay of plasm cortisol.
We report a simplified radioimmunoassay procedure for determination of plasma cortisol. The method offers the advantage that tracer, antibody, and assay buffer are added in a single step with the use of semi-automated equipment. Thus, critical pipetting procedures are minimized, and assay time is reduced to 4 h. No prior extraction or chromatographic purification of cortisol is required. The procedure is simple, reliable, and accurate. For either between-assay or within-assay determinations, the coefficients of variation are about 6%. Our results compare well with those obtained from a procedure that included extraction and chromatographic purification of cortisol in several plasma samples. Conditions for optimizing the assay are also discussed.
D001322:Autoanalysis; D002021:Buffers; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007106:Immune Sera; D011863:Radioimmunoassay / Q000379:methods; D014316:Tritium
D002021:Buffers; D007106:Immune Sera; D014316:Tritium; D006854:Hydrocortisone