Quantitative determination of dibekacin using radioimmunoassay, substrate-labelled fluorescent immunoassay and rate nephelometric inhibition immunoassay for tobramycin.

Radioimmunoassay, rate nephelometric inhibition immunoassay and substrate-labelled fluorescent immunoassay were employed for the quantitative determination of dibekacin in serum. The cross-reactivity of the antibody provided with each assay allowed the use of tobramycin assay procedures for measuring dibekacin concentrations. With radioimmunoassay and nephelometric immunoassay, a dibekacin calibration curve was required, whereas fluorescent immunoassay was directly suitable for dibekacin assay, with cross-reactivity of nearly 100%. This allows the purchase of one assay kit for testing two antibiotics and thus reduces the cost to medical laboratories.