Further studies on radioimmunoassay systems for plasma oestradiol

A systematic study has been made of alternative procedures in a liquid phase radioimmunoassay system for the determination of oestradiol in peripheral venous plasma from men and women. Accordingly, the relative merits of two radionuclides, three antisera, four separation techniques and three methods of measuring radioactivity have been determined. The results show that the most accurate values are obtained if an antiserum to oestradiol-6-carboxymethyl oxime is used, and that a chromatographic step is not required for routine assays. In addition, the values for precision, sensitivity and accuracy are similar, whether [2,4,6,7- 3H]-oestradiot or oestradiol-6-carboxymethyl oxime-mono 125 iodohistamine is used as labelled tracer. Marginally lower (