title: An enzyme immunoassay for secretin.
abstract: A sensitive and specific enzyme immunoassay for secretin was developed with the use of enzyme-labeled antigens. Synthetic porcine secretin and its carboxy-terminal fragments (residues 11-27 and 18-27) were conjugated with beta-D-galactosidase for use in the immunoassay, and the assay method with the latter fragment (residues 18-27) linked to beta-D-galactosidase was found to be the most sensitive. The minimum amount of secretin detectable by this method was 1-2.5 pg/assay. Serum levels of secretin after intravenous injection of the peptide in rats were determined by both the enzyme immunoassay and a commercial radioimmunoassay kit. The correlation coefficient between the levels measured by the two methods was 0.984. The enzyme immunoassay could detect immunoreactive secretin levels in normal human sera, giving a value of 16.9 +/- 2.2 pg/ml (mean +/- SE of six human subjects).
mesh_terms: D000818:Animals; D000917:Antibody Formation; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012633:Secretin / Q000097:blood* / Q000276:immunology; D001616:beta-Galactosidase / Q000276:immunology
chemical_list: D012633:Secretin; D001616:beta-Galactosidase