EVALUATION OF A NOVEL FLUORESCENCE POLARIZATION IMMUNOASSAY FOR TEICOPLANIN

A fluorescence polarization immunoassay (FPI) for teicoplanin that use s the TDx Instrument System (Abbott, Irving, Tex.) as an automated ana lyzer has been developed by Innotron of Oregon Inc. and was evaluated in patients with staphylococcal infections enrolled in a clinical tria l of the antibiotic. The assay proved accurate in estimating concentra tions of between 5 and 100 mg/liter. The intraassay coefficient of var iation was <7.3%, while the interassay variance was <11.6% against thr ee commercially prepared standards at known concentrations of approxim ately 5, 35, and 75 mg/liter. Against routinely prepared standards at 10 concentrations between 5 and 100 mg/liter analyzed in a single run, the coefficient of variance did not exceed 4.3%. Compared with bioass ay, the FPI demonstrated good correlation in terms of reliability (r = 0.909) in samples containing teicoplanin only and specificity (r = 0. 916) in samples containing both teicoplanin and gentamicin. With a tur naround time of 20 min and with only 50 mul of serum needed for estima tion of the amount of drug in a sample, the FPI described here should provide a useful method of teicoplanin measurement in routine diagnost ic laboratories.