title: An enzyme-linked immunosorbent assay for fetal steroid binding protein of human serum.
abstract: The binding characteristics and quantitation of the recently reported fetal steroid binding protein (FSBP) cannot be determined on unpurified samples; an immunoassay was therefore desirable. The protein was purified to homogeneity in order to raise a highly specific polyclonal antibody. An enzyme-linked immunosorbent assay applicable to unpurified samples was developed. Intra- and inter-assay coefficients of variation are 8.0% and 9.2% respectively; there is a sensitivity of 30 fmol FSBP per well, and there is no cross-reactivity with other binding proteins. Results obtained with the assay correlate with the more complex ligand binding assay (r = 0.85; p less than 0.02). Measurement of sera showed that FSBP levels are higher in women than in men (51.2 +/- 10.62 nM; 41.2 +/- 13.65 respectively; p less than 0.05) and are elevated in cirrhotic women (66.4 +/- 18.67; p less than 0.05) and in males with hepatocellular carcinoma (62.2 +/- 13.05; p less than 0.002). Use of the enzyme-linked immunosorbent assay confirmed the identity of FSBP separate from sex hormone binding globulin.
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000097:blood; D002352:Carrier Proteins / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005333:Fetus; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood; D008113:Liver Neoplasms / Q000097:blood; D008297:Male; D011247:Pregnancy; D011786:Quality Control; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013256:Steroids / Q000097:blood
chemical_list: D002352:Carrier Proteins; D012738:Sex Hormone-Binding Globulin; D013256:Steroids