Evaluation of four gentamicin and tobramycin assay procedures for clinical laboratories.
Accuracy, precision, and clinical laboratory utility of the TDX (Abbott Laboratories), Auto-ICS (Beckman Instruments, Inc.), COBAS-Bio (Roche Analytical Instruments, Inc.) with reagent kits (Syva), and EMIT (Syva) for gentamicin and tobramycin serum assay were assessed. TDX, COBAS-Bio, and EMIT analytical systems showed a proportional bias of less than 10% for recovery studies and a coefficient of variation less than 5% for within-run precision. The results of the recovery studies with the Auto-ICS showed a proportional bias of 25% with gentamicin and 16% with tobramycin. The within-run precision expressed as the coefficient of variation for the Auto-ICS was 6.7% for gentamicin and 8.6% for tobramycin. In comparisons involving gentamicin- and tobramycin-containing patient samples, the results with the TDX analytical system showed the best agreement with the COBAS-Bio. For the determination of these two antibiotics, the TDX analytical system provided the best overall accuracy and precision.
D005839:Gentamicins / Q000097:blood*; D006801:Humans; D007753:Laboratories / Q000592:standards*; D011933:Reagent Kits, Diagnostic; D014031:Tobramycin / Q000097:blood*
D005839:Gentamicins; D011933:Reagent Kits, Diagnostic; D014031:Tobramycin