A simple micro agar diffusion method for the determination of antibiotic concentrations in blood and other body fluids.

A micro agar diffusion method to determine antibiotic levels in only 0.02 ml of serum is described. With this technique, standard curves for Ampicillin, Penicillin G, Gentamicin, Tetracycline HCl and Amphotericin B were calculated. The method displays a good reproducibility with an error of less than 10%. To compare this technique with a conventional macro agar diffusion method fixed antibiotic concentrations in rabbit serum were examined. Corresponding results were obtained indicating the equivalence of this method, which thus proved to be suitable to determine antibiotic levels in small volumes of body fluids.