Unconjugated 5 alpha-androstan-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol in human plasma as measured by radioimmunoassay without chromatography.

A radioimmunoassay (RIA) without chromatography for the determination of 5 alpha-androstan-3 alpha, 17 beta-diol and of 5 alpha-androstane-3 beta, 17 beta-diol in human plasma by using highly specific antisera against the 15 beta-carboxyethylmercapto-bovine serum albumin conjugates is described. It could be shown that the 13% cross reaction of the 5 alpha-androstane-3 beta, 17 beta-diol antiserum with pure androst-5-ene-3 beta, 17 beta-diol was negligibly low in plasma extracts. Sensitivity, accuracy, precision, and linearity revealed results which comply with the requisites of a reliable RIA. The plasma levels obtained were as follows (mean +/- SD): 5 alpha-androstan-3 alpha, 17 beta-diol: Normal males (N = 27) 0.86 +/- 0.22 nmol/l; normal females (N = 10) 0.31 +/- 0.07 nmol/l; hirsute females (N = 25) 0.60 +/- 0.24 nmol/l; 5 alpha-androstane-3 beta, 17 beta-diol: Normal males 1.47 +/- 0.43 nmol/l; normal females 0.49 +/- 0.10 nmol/l; hirsute females 0.91 +/- 0.32 nmol/l.