Comparison of a fluorescent immunoassay with an enzyme immunoassay and a radioimmunoassay for gentamicin.
A fluorescent immunoassay (FIA) for gentamicin was evaluated and compared with an enzyme multiplied immunoassay (EMIT) and a radioimmunoassay (RIA) for gentamicin. Pooled human serum that contained low, medium, and high concentrations of gentamicin sulfate (approximately 2.5, 5, and 10 micrograms/ml of gentamicin) were analyzed for actual gentamicin concentration by FIA. Samples were assayed 10 times during the same day to evaluate within-run precision and on 10 different days to evaluate between-run precision. Serum samples obtained from patients receiving gentamicin therapy were analyzed for gentamicin concentration using FIA and EMIT, and separate serum samples were analyzed using FIA and RIA. Results were compared by regression analysis. Within-run coefficients of variation were 8.47%, 6.84%, and 2.62%, respectively, for the low, medium, and high concentrations of gentamicin, and the respective between-run coefficients of variation were 10.81%, 6.31%, and 1.64%. The correlation coefficient for the comparison of FIA with EMIT was 0.943, and the correlation coefficient for the comparison of FIA with RIA was 0.970. The fluorescent immunoassay is a reliable method for determining the concentration of gentamicin in serum. Although the results obtained by FIA correlate well with those obtained by EMIT and RIA, variability exists between concentrations determined by each of these methods.
D005069:Evaluation Studies as Topic; D005455:Fluorescent Antibody Technique; D005839:Gentamicins / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D011863:Radioimmunoassay / Q000379:methods; D011933:Reagent Kits, Diagnostic
D005839:Gentamicins; D011933:Reagent Kits, Diagnostic