Application of radioimmunoassay (RIA) for the determination of residues of anabolic sex hormones.

Based on the basic principles of radioimmunoassay (RIA), it can be expected that by using this method, residues of anabolic sex hormones in animal tissues can be quantitated in the ng/g to pg/g range with adequate reliability. This was demonstrated for various endogenous and exogenous steroids as well as for stilbene-estrogens. Using the RIA for DES as a regulatory method allowed the successful control of the misuse of this compound in animal production, especially by examination of excreta. Also, for muscular tissue, an interlaboratory validation study yielded acceptable results. The need for confirmatory methods is stressed.