Comparison of a radioimmunoassay with an enzymatic assay for gentamicin.

A radioimmunoassay and an enzymatic assay for gentamicin have been compared. The correlation coefficient for results of gentamicin assays performed by the two methods with 45 serum specimens was 0.90. A similar standard curve for the radioimmunoassay was obtained with gentamicin complex, with gentamicin Cl, Cla, or C2, or with sisomicin as ligand, but tobramycin did not compete with [(3)H]gentamicin for binding to the antiserum.