title: A thyrotropin radioimmunoassay kit evaluated vs two reference assays.
abstract: We evaluated a double-antibody radioimmunoassay kit for thyrotropin that includes calibrators prepared in a matrix of human serum and involves overnight nonequilibrium. Results were compared with those from two reference assays for thyrotropin. The range of within-assay CVs for the kit for thyrotropin values between 0.9 and 2.4 milli-int. units/L was 2.2 to 5.3%, that for between-assay CVs was 8.3 to 30%. The estimated minimum detectable concentration of thyrotropin was 0.6 milli-int. unit/L. We saw no cross reactivity with human choriogonadotropin by any of 48 sera from pregnant women. The original lot of serum specified as thyrotropin-free contained small but measurable amounts of thyrotropin; a second lot did not. Clinical data generated with the kit and the reference assays correlated well and were consistent with the clinical status of various categories of patients.
mesh_terms: D006063:Chorionic Gonadotropin / Q000097:blood; D003429:Cross Reactions; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood; D011247:Pregnancy; D011863:Radioimmunoassay / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D013972:Thyrotropin / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D011933:Reagent Kits, Diagnostic; D013972:Thyrotropin