Performance assessment of the GammafloTM automated radioimmunoassay system by assaying for digoxin.

We report an evaluation of the GammafloTM automated continuous-flow radioimmunoassay instrument in which we used a digoxin assay to assess system performance. System operation was based on combined continuous-flow and column-chromatographic techniques. No drift or carryover was detectable in 180 within-assay consecutive determinations performed at a rate of 42 determinations per hour (5 h of continuous operation). Within-assay and between-assay precision were less than 6% (coefficient of variation). The automated method correlated well (r = 0.960 and 0.952, respectively) with two established manual digoxin radioimmunoassay procedures. The data suggest this automated system offers a valid alternative to manual radioimmunoassay procedures in terms of overall precision, simplicity of operation, and sample throughout capacity.