Comparison of enzyme-multiplied immunoassay technique with fluorescence polarization immunoassay for determination of gentamicin and tobramycin levels in serum.

We assayed serum gentamicin and tobramycin specimens by the enzyme multiplied immunoassay technique (Syva EMIT) and the fluorescence polarization immunoassay (Abbott TDx). When interassay and intraassay control samples were evaluated, both methods gave an overall coefficient of variation of less than +/- 10%. Using patient serum samples, we obtained excellent correlation with both methods in the assay of gentamicin (correlation coefficient, 0.985) and tobramycin (correlation coefficient, 0.982).