Radioimmunoassay of anabolic steroids: an evaluation of three antisera for the detection of anabolic steroids in biological fluids.

Recently developed radioimmunoassays (RIA) for the analysis of anabolic steroids and their metabolites in biological fluids were tested for cross-reactivity with other types of steroids. Results show that the degree of desirable cross-reactivity within the two classes or orally active anabolic steroids vary widely and that the antiserum for 19-Nortestosterone (the active principle of intramuscular preparations) has a very high degree of undesirable cross-reactivity with components of oral contraceptives. Single and multiple dose studies in human volunteers demonstrate that the detection level and degree of retrospectivity are likewise variable but that the test easily detects most anabolic steroids during treatment. At the present time, the combination of the three antisera for the assay of a sample appears to be a relatively rapid and economic method for screening large numbers of samples in situations where doping control of anabolic steroids is required. The importance of utilizing physico-chemical means for identification of RIA potential positives is emphasized.