[A simple method for radioimmunoassay of total estrogen in urine]

A simple and rapid radioimmunoassay (RIA) without extraction or purification was developed for Total Estrogen (conjugated and unconjugated estrogen) in urine from normal men and nonpregnant women. Antiserum used to RIA was produced by immunizing rabbits with estriol-16 alpha-glucuronide (E3-16-G)-BSA conjugates. Antiserum to E3-16-G.BSA significantly cross-reacted with E1 (100%), E2 (100%), E3 (100%), E3-16-G (100%), AND E3-17-G (100%) and did not react with other conjugated estrogen in urine. Urinary estrogen glucuronides and sulfates were gently hydrolyzed by beta-glucuronidase from Helix pomatia juice for 2hr (48 degrees C) without inhibition, and hydrolysis urine was directly applied to RIA. The results obtained from this direct method correlated well with the chromatographic purificating method, the extracting method and the Brawn-Kambegawa method (colorimetric method). This direct method is very useful for clinical application.