Correlation between fluorimetric and microbiological methods for determination of cephalexin in urine and serum.

The fluorimetric and microbiological methods for the determination of serum and urine cephalexin were compared with the aid of coded samples in two different laboratories. The coefficient of correlation between the two methods for serum cephalexin was 0.94. At urine cephalexin concentrations above 0.5 g/l, the coefficient of correlations between two methods was 0.83. At lower concentrations (0.5 g/l), the coefficient of correlation was 0.72. It was concluded that the tested methods are comparable, equally sensitive and precise.