Comparison of bioassay, high-performance liquid chromatography, and fluorescence polarization immunoassay for quantitative determination of vancomycin in serum

This investigation was designed to compare three assay techniques, the traditional bioassay (agar diffusion), and two more recent techniques, high-performance liquid chromatography (HPLC) and fluorescence polarization immunoassay (FPIA), for the determination of vancomycin concentrations in serum. One hundred clinical samples obtained from patients receiving vancomycin were assayed by each method. The results from each assay were compared using linear regression analysis. The resultant correlation coefficients were as follows: 0.9996 for the HPLC versus FPIA, 0.7773 for the FPIA versus bioassay, and 0.7779 for HPLC versus bioassay. The FPIA technique was the easiest and fastest of the three methods; FPIA and HPLC were the most accurate.