ALBERT, A.

Abstract Radioimmunoassay of serum estrogen (sum of estrone and estradiol-17β) in 0.5 ml of human serum is described. After dilution of the serum, the estrogens are adsorbed on a Sephadex G-15 column in the presence of dilute HCl and then eluted with benzene. After evaporation of the benzene eluate, the estrogens are dissolved in bovine serum albumin (5 g/ liter solution, at pH 8.0). An aliquot of this solution is used for the assay. Serum estrogen concentrations (mean ± SD) were 69 ± 23 pg/ml in 105 normal men and 199 ± 146 pg/ml in 26 fertile women. In 109 postmenopausal women, estrogen was undetectable in seven sera, but in the remaining 102 it was 52 ± 30 pg/ml of serum.