Evaluation of an automated system (Optimate) for substrate-labeled fluorescent immunoassays

Performance characteristics of substrate-labeled fluorescent immunoassays for the drugs phenytoin, phenobarbital, primidone, carbamazepine, theophylline, gentamicin, tobramycin, amikacin, and quinidine run on an Optimate automated fluorometric analyzer were compared with those of automated enzyme multiplied immunoassays (EMIT) for the same drugs performed on a Cobas centrifugal analyzer for patient samples and controls. For 100 patient samples assayed by both systems for each drug, excellent correlations were obtained, with correlation coefficients ranging from 0.96 to 0.99. Likewise, very good within-run (n = 10) and between-run (n = 30) precision was obtained by both methods. Values for controls and clinical specimens by the Optimate methods calculated using the same-day calibration curves were not significantly different from those calculated from calibration curves stored 14 days, indicating at least 14-day curve stability for all assays.