Comparison of chemical and radiochemical methods in the measurement of steroid hormones

The comparative merits and difficulties of chemical and radioimmunoassay methods (RIA) for the measurement of steroid hormones are discussed. An advantage of RIA is that is some cases steroids can be measured directly in serum or plasma thereby simplifying operations but in other cases especially when analyses are carried out in urine the samples must be thoroughly and accurately processed before RIA can be performed. The operations involved in the preparation of urine or blood samples suitable for the RIA of steroid hormones are examined and compared in terms of practicability with the analytical procedures currently used for the chemical determination of the same steroids or their metabolites. The fact that RIA while constituting a great technical advance is still subject as are the traditional methods to the risk of contamination and interferences during the preliminary preparation of the samples. Therefore great care and accuracy at this stage and in performing the analyses as well as thorough testing of commercially supplied RIA kits are still essential requirements.(Authors modified)