Vancomycin Microbial Assay Using Kinetic-Reading Microplate System

The aim of this work was to develop a microbiological assay of vancomycin employing microplates and kinetic reading mode, and to validate the developed method by assessing of specificity and selectivity, linearity, linear range, accuracy and precision parameters. Established conditions comprised a vancomycin standard-curve in concentrations from 0.6 to 1.0 μg mL-1, and soybean-casein broth inoculated with 5% of Bacillus subtilis (ATCC 6633) suspension. Satisfactory results were obtained after a 5 hour incubation. The developed method showed appropriate selectivity and linearity in the range from 0.6 to 1.0 μg mL-1, respectively, satisfactory accuracy (recovery = 97.0%) and precision (RSD = 7.8%).