Direct solid-phase time-resolved fluoroimmunoassay of 17 alpha- hydroxyprogesterone in serum and dried blood spots on filter paper

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 36; no. 9; pp. 1667 - 1672
• Main Authors: Gonzalez, RR, Maentausta, O, Solyom, J, Vihko, R
• Format: Journal Article
• Language: English
• Published: Washington, DC Am Assoc Clin Chem 01.09.1990; American Association for Clinical Chemistry
• Subjects: 17-alpha-Hydroxyprogesterone; Adolescent; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Blood Stains; Child; Child, Preschool; Europium; Female; Fluoroimmunoassay; Fundamental and applied biological sciences. Psychology; Humans; Hydroxyprogesterones - blood; Hydroxyprogesterones - immunology; Infant, Newborn; Male; Other biological molecules; Radioimmunoassay; Terpenes, steroids. Hormones; Human; Steroid; Biological fluid; Filter paper; Enzyme immunoassay; Complexes; Blood; Fluorescent labelling; Clinical biology; Serum; Solid phase; Europium; Quantitative analysis
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/36.9.1667

We describe a direct, solid-phase time-resolved fluoroimmunoassay (TRFIA) for measuring 17 alpha-hydroxyprogesterone (17OHP) in serum and blood spots on filter paper. We used 17OHP-3-carboxymethyloxime (17OHP3CMO) coupled to polylysine as the label, which enabled incorporation of up to 34 atoms of europium per molecule of 17OHP, for a very high specific activity. The assay is based on competition between labeled 17OHP3CMO and 17OHP in blood specimens for polyclonal rabbit anti-17OHP antibodies. The antibody-label complex is separated by binding to anti-rabbit antibodies coated onto microtiter strips. The assay buffer contains danazol to displace 17OHP from steroid-binding proteins in serum. For serum samples, the assay is accomplished in 1 h of incubation at room temperature. The blood spot assay with filter paper discs involves incubation overnight at 4 degrees C. Results for both types of specimens from the same subjects correlated well. The lowest measurable concentrations of 17OHP (nmol/L) were 0.10 (3 SD) and 0.75 (3 SD) for serum and dried blood on filter paper, respectively. Intra- and interassay CVs were about 5-15% for both types of samples.