title: A comparison of automated and manual radioimmunoassays for the estimation of serum digoxin.
abstract: Digoxin was assayed manually (SPAC kit) and by an automated radioimmunoassay instrument (ARIA II). There was good correlation between the methods (r = 0.964; n = 120). Carryover by the automated method was marginally significant from low to high level samples (5.2%), but insignificant from high to low level samples (1.4%). The precision on the ARIA II was far better in spite of the fact that assays were performed only in singlets compared with duplicates on the manual procedure. Best precision was obtained at the high level (3.76 nmol/l; between-batch CV: 2.4% ARIA; 5.5% SPAC). All values for control samples (manual and automated) fell within 6% of the all-method means. Using the ARIA II is marginally quicker and significantly cheaper. However, some back-up procedure is required for 'down time' with the machine, for what can be an urgent investigation. Patient results correlated well with clinical data.
mesh_terms: D000368:Aged; D001322:Autoanalysis / Q000295:instrumentation; D004077:Digoxin / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods; D011933:Reagent Kits, Diagnostic
chemical_list: D011933:Reagent Kits, Diagnostic; D004077:Digoxin