[Assay of aminoglycosides in serum using the urease method].

The urease method developed byNoone et al. for rapid bioassay of aminoglycoside antibiotics in serum is described in detail. The accuracy of the method was improved by using a BM 1-09 electrode assembly (Metrohm, CH-9100 Herisau, Switzerland) in conjunction with a digital pH-Meter (Metrohm E 500). The mean difference between spiked serum samples and measured concentrations was +0.37±0.78µg/ml. The coefficient of determination between the urease and agar diffusion method was 0.94. Disadvantages of the method are a low sensitivity at concentrations below 1.5µg/ml and a large serum sample (1.5 ml). Advantages are its simplicity and rapidity.