Development and application of a fully automated continuous flow radioimmunoassay system.
- G C Forrest
- Annals of clinical biochemistry
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 tl) and the reproducible timing enables nonequilibrium conditions to be used. Thus a single sample is assayed in 15 mm, with a sample throughput of 30/h. The standard curve ranges from 0.5 to 8.0 zg/llter and is most precise between 1 and 3 tg/liter, the between-assay coefficient of variation being less than 3%. There isno 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.