title: Automated fluorescence polarization immunoassay for monitoring vancomycin.
abstract: We have extended fluorescence polarization immunoassay (FPIA) technology for the measurement of drugs to include the complex amphoteric glycopeptide antibiotic vancomycin (molecular weight, 1,449). Fluorescein-labeled vancomycin was employed as a tracer, and antisera specific for vancomycin were raised in rabbits by conventional procedures. Tracer, sample, and diluted antiserum were combined, and the polarization of tracer fluorescence is determined in a specially designed fluorometer (Abbott TDx). Because of instrument design, the possibility of fluorescent interferences is minimized. The assay can measure as little as 0.6 mg/L of vancomycin and is free of interferences from hemolysis, lipemia, bilirubin, and changes in protein concentration. The coefficient of variation within assay was 3% (n = 5) and between assays was 5% (n = 5). The FPIA assay (TDx Vancomycin) was compared to a liquid chromatographic (LC) assay for vancomycin and to a commercially available radioimmunoassay (RIA) for 98 clinical specimens. A linear least-squares regression analysis gave a correlation coefficient for LC of 0.980 from the equation FPIA = 1.09 LC + 3.04, and a correlation coefficient for RIA of 0.957 from the equation FPIA = 1.036 RIA + 1.66.
mesh_terms: D000918:Antibody Specificity; D003429:Cross Reactions; D005454:Fluorescence Polarization; D006801:Humans; D007118:Immunoassay / Q000379:methods; D014640:Vancomycin / Q000097:blood*
chemical_list: D014640:Vancomycin