Spectrophotometric assay for amikacin using purified kanamycin acetyltransferase.

A rapid spectrophotometric assay has been developed for measuring the concentrations of amikacin and related antibiotics in serum. The assay uses a purified enzyme from R-factor E. coli which acetylates amikacin with the production of coenzyme A, the latter in turn being reacted with a sulfhydryl reagent to produce stoichiometric amounts of a sensitive chromophore, that is measured in the visible spectrum. The system complements an earlier assay for gentamicin-related antibiotics thereby facilitating the rapid measurement of the concentrations of all clinically important aminoglycosides in serum.