Radioimmunoassay for digoxin with a fully automated continuous-flow system.
We describe a fully automated continuous-flow radioimmunoassay for digoxin with use of a Technicon AutoAnalyzer system. It makes use of antibodies linked to magnetizable particles; a magnet separates the bound and free fractions. The precise dispensing of reagents by the AutoAnalyzer system permits a small incubation volume (about 160 microliter) and the reproducible timing enables non-equilibrium conditions to be used. Thus a single sample is assayed in 15 min, with a sample throughput of 30/h. The standard curve ranges from 0.5 to 8.0 microgram/liter and is most precise between 1 and 3 microgram/liter, the between-assay coefficient of variation being less than 3%. There is no significant carryover between samples of high and low concentration, and results by the method correlate closely (r = 0.969) with those by an established manual assay in which charcoal separation is used.
D000918:Antibody Specificity; D001322:Autoanalysis; D003429:Cross Reactions; D004077:Digoxin / Q000097:blood* / Q000276:immunology; D006801:Humans; D007457:Iodine Radioisotopes; D008280:Magnetics; D011485:Protein Binding; D011863:Radioimmunoassay / Q000379:methods
D007457:Iodine Radioisotopes; D004077:Digoxin