title: Nonchromatographic radioimmunoassay of unconjugated estriol in plasma, with polyethylene glycol as precipitant.
abstract: We describe a rapid, reliable radioimmunoassay for unconjugated estriol in plasma. Polyethylene glycol (Carbowax 6000) is used to separate antibody-bound and free steroid. The assay is sensitive (25 pg for standards), precise, and accurate. At high and low concentrations of estriol, intra-assay coefficients of variation were 7.1% and 7.6%, respectively, and inter-assay coefficients of variation were 7.2% and 10.0 %, respectively. Free [3H] estriol is not precipitated by polyethylene glycol. This radioimmunoassay of estriol, with a highly specific antiserum and with polyethylene glycol as the antibody precipitant, is a reliable one-day assay that is practical both for the clinical laboratory and the obstetrician.
mesh_terms: D000704:Analysis of Variance; D003429:Cross Reactions; D004964:Estriol / Q000097:blood*; D005260:Female; D008832:Microchemistry; D011092:Polyethylene Glycols; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011863:Radioimmunoassay / Q000379:methods; D012995:Solubility
chemical_list: D011092:Polyethylene Glycols; D004964:Estriol