Biomaterial Database

125I-radioimmunoassay for unconjugated estriol in serum of pregnant women. 1978

R J Liedtke, and J P Greaves, and J D Batjer, and B Busby

An 125I-radioimmunoassay is described which measures unconjugated estriol in the serum of pregnant women. Estriol is extracted into ethyl acetate/hexane, an aliquot is evaporated, and the residue is redissolved in phosphate buffer. The sample is incubated with tracer and antibody at 37 degrees C for 15 min and then at 4 degrees C for 1 h and 45 min. The antibody-bound fraction is then precipitated with polyethylene glycol and isolated by centrifugation. Because the antigen-antibody complex is stable in the presence of polyethylene glycol, the separation steps are not influenced by timing. Extraction recovery of 3H-labeled estriol added to a pool of sera from pregnant women averaged 96.7% (SD = 1.3, n = 10). Estriol-supplemented (5, 10, and 20 microgram/liter) serum from men, carried through the entire procedure, showed analytical recovery ranging from 94 to 106%. Structurally analogous steroids normally present in serum of pregnant women exhibit negligible cross reactivity. Day-to-day precision (CV) is 13.3% (3.1 microgram/liter), 6.4% (7.6 microgram/liter), and 5.6% (21.4 microgram/liter) for n = 21. The current reagent cost (about 17 cents per tube), and a total procedural time, including counting, of 5.5 h make this an acceptable assay for routine use.

UI	MeSH Term	Description	Entries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011263	Pregnancy Trimester, Third	The last third of a human PREGNANCY, from the beginning of the 29th through the 42nd completed week (197 to 294 days) of gestation.	Pregnancy, Third Trimester,Trimester, Third,Last Trimester,Last Trimesters,Pregnancies, Third Trimester,Pregnancy Trimesters, Third,Third Pregnancy Trimester,Third Pregnancy Trimesters,Third Trimester,Third Trimester Pregnancies,Third Trimester Pregnancy,Third Trimesters,Trimester, Last,Trimesters, Last,Trimesters, Third
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D004964	Estriol	A hydroxylated metabolite of ESTRADIOL or ESTRONE that has a hydroxyl group at C3, 16-alpha, and 17-beta position. Estriol is a major urinary estrogen. During PREGNANCY, a large amount of estriol is produced by the PLACENTA. Isomers with inversion of the hydroxyl group or groups are called epiestriol.	(16alpha,17beta)-Estra-1,3,5(10)-Triene-3,16,17-Triol,(16beta,17beta)-Estra-1,3,5(10)-Triene-3,16,17-Triol,16-alpha-Hydroxy-Estradiol,16alpha,17beta-Estriol,16beta-Hydroxy-Estradiol,Epiestriol,Estra-1,3,5(10)-Triene-3,16beta,17beta-Triol,Ovestin,16 alpha Hydroxy Estradiol,16alpha,17beta Estriol,16beta Hydroxy Estradiol
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man