title: An immunoradiometric assay for measurement of serum thyroglobulin.
abstract: A two-site immunoradiometric assay (IRMA) for estimation of serum thyroglobulin (tg) is optimized using partially purified rabbit anti-tg antibodies (ammonium sulphate precipitated) as a solid phase antibody and affinity purified 125I labeled anti-tg antibodies as a tracer. The IRMA correlated well (r = 0.93, n = 200, P < 0.001) with conventional radioimmunoassay (RIA). The inter- and intra-assay coefficient of variation were comparable for both methods. The IRMA method gave a superior sensitivity and working range (2 ng/ml, 3-1000 ng/ml) as compared to that of RIA method (6 ng/ml, 9-500 ng/ml). Using IRMA the total incubation time was curtailed to 4 h as compared to 90 h required for conventional RIA. The shelf-life of tracer antibody used in IRMA was much longer (3 months) as compared to tracer tg (3-4 wk) used in RIA. The optimized IRMA for quantitation of serum tg has superior assay characteristics as compared to RIA.
authors.affiliation: Radiation Medicine Centre, Bhabha Atomic Research Centre, Bombay.
authors.forename: B
authors.initials: B
authors.lastname: Rajashekharrao
authors.forename: A
authors.initials: A
authors.lastname: Kumar
authors.forename: A
authors.initials: A
authors.lastname: Velumani
authors.forename: D H
authors.initials: DH
authors.lastname: Shah
mesh_terms: D006801:Humans; D015592:Immunoradiometric Assay; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood*
chemical_list: D013954:Thyroglobulin