SPECIFIC RADIOIMMUNOLOGICAL DETERMINATION WITHOUT CHROMATOGRAPHY OF PLASMA OESTRADIOL IN MALES

Abstract

A hapten-radioimmunoassay of plasma oestradiol consisting of an extraction procedure and a final assay using a highly specific antiserum to oestradiol (obtained by immunization of rabbits with oestradiol-6-carboxymethoxime-BSA) was compaired with a similar procedure including a TLC step the specificity of which and other reliability criteria were already established. The plasma oestradiol from 24 normal adult males analysed by both methods showed a fairly close agreement (y = 0.97 x). Pooled normal male plasma analysed in the same way did not reveal any difference: 20.5 ± 0.34 vs. 20.5 ± 0.44 (x̄ ± sem reference method vs. method without TLC). The between-assay-precision of the method without TLC was 10.9% (C. V.), the mean blank 0.8 pg, the sensitivity in terms of 99 % confidence limit of the reagent blank 7.8 pg and the overall tracer recovery 73 %.