title: Measurement of insulin in human sera using a new RIA kit. 1. Insulin determination in the absence of insulin antibodies--conventional assay and micro modification.
abstract: A sensitive and versatile radioimmunoassay (RIA) for insulin was established using human insulin standard, a specific guinea pig anti-insulin antiserum and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations were used for as long as 6 weeks after iodination. The standard curve ranges from 0.044 to 1.2 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.4 and 0.9 nmol/l. The average recovery of human insulin added to plasma or serum samples was 100.2 +/- 2.0% (n = 38) and 100.1 +/- 1.9% (n = 42), respectively. In addition to human insulin, porcine, canine, rabbit and bovine insulin can also be determined but not rat or mouse insulin. The cross-reactivity of the antiserum with porcine proinsulin was found to be 40% on the molar basis. The range of mean fasting plasma insulin concentrations in healthy subjects and under various pathological conditions were estimated.
authors.affiliation: Central Institute of Diabetes Gerhardt Katsch, Karlsburg, GDR.
authors.forename: W
authors.initials: W
authors.lastname: Besch
authors.forename: K P
authors.initials: KP
authors.lastname: Woltanski
authors.forename: H
authors.initials: H
authors.lastname: Keilacker
authors.forename: J M
authors.initials: JM
authors.lastname: Diaz-Alonso
authors.forename: B
authors.initials: B
authors.lastname: Schulz
authors.forename: P
authors.initials: P
authors.lastname: Amendt
authors.forename: K D
authors.initials: KD
authors.lastname: Kohnert
authors.forename: M
authors.initials: M
authors.lastname: Ziegler
mesh_terms: D006801:Humans; D007328:Insulin / Q000097:blood*; D007330:Insulin Antibodies / Q000032:analysis; D011863:Radioimmunoassay; D011933:Reagent Kits, Diagnostic
chemical_list: D007328:Insulin; D007330:Insulin Antibodies; D011933:Reagent Kits, Diagnostic