Adaptation of the EMIT serum digoxin assay to a mini-disc centrifugal analyzer

We have modified the EMIT (Syva) serum digoxin assay for use with a mini-disc centrifugal analyzer. A minicomputer is used to control data acquisition, calculations, and readout for 14 cuvettes simultaneously. Thus, it is not necessary for time each individual assay manually or to plot calibration curves on graph paper. We use incubation times and dilutions similar to those used for the manual procedure, but we have changed the buffer solution, decreased the measurment time, and decreased the required serum volume per assay fivefold. We evaluated day-to-day and within-run precision, using Syva calibrators and control sera. EMIT assay values for radioimmunoassay control sera correlate well with the supplier's stated values.