Nonchromatographic Radioimmunoassay of Plasma 11-Deoxycortisol, for Use in the Metyrapone Test, with Polyethylene Glycol as the Precipitant

Autor: Lilian M. Y. Lee, Harvey S. Schiller
Rok vydání: 1975
Předmět:
Zdroj: Clinical Chemistry. 21:719-724
ISSN: 1530-8561
0009-9147
DOI: 10.1093/clinchem/21.6.719
Popis: We have developed a simple, reliable radioimmunoassay for plasma 11-deoxycortisol. The method does not require chromatography but instead makes use of a simple extraction procedure which, in combination with the antibody characteristics, is highly specific for the metyrapone test. Polyethylene glycol was used to separate free and antibody-bound steroid. The smallest amount measurable is 15 pg (2.0 µg/ liter of plasma). The method is shown to be precise and accurate. Intra-assay precision of the method for two plasma pools was 26.7 ± 2.5 µg/ liter (CV = 9.4%) and 61.2 ± 3.7 µg/ liter (CV = 6.0%). The respective inter-assay precision was 27.0 ± 1.7 µg/ liter (CV = 6.3%) and 59.9 ± 2.3 µg/ liter (CV = 3.8%). The validity of the assay was further verified by evaluating the plasma 11-deoxycortisol response to metyrapone administration. The relative simplicity of the method and the commercial availability of all reagents, including antisera, makes this radioimmunoassay procedure practical for use in clinical laboratories.
Databáze: OpenAIRE