Rapid micromethod for aminoglycoside assays in serum by utilization of bacterial reduction of nitroblue tetrazolium.

The rapid assay of aminoglycoside concentrations in serum, based upon the decreased ability of bacteria to reduce nitroblue tetrazolium (NBT) in the presence of antibiotics, has now been modified for micro-analysis of capillary blood. The volume of serum needed is 50 μl. The reproducibility of the method was tested by repeated assays of 10 artificial serum samples containing gentamicin in concentrations 0.4 to 4.0 mg/l. The standard deviation of the method was 10.6%. When 20 serum samples from patients treated with gentamicin were analysed by means of the NBT microassay and by a conventional disc diffusion method a good correlation ( = 0.96) was obtained. [ABSTRACT FROM PUBLISHER]