Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) Tests

Purpose of Test

As an adaptation of the clinical susceptibility tests commonly used to determine effective concentrations of antibiotics, the MIC and MBC test method can be performed as a presumptive way to screen active concentrations of a product. This method is not typically used to generate antimicrobial claims with a specific regulatory agency but rather can be used to quickly narrow down effective concentrations of a product’s active ingredient.

Summary of Test

In this method, a series of product dilutions are placed into a 96-well plate. The wells containing the various product concentrations are then inoculated with test organisms of interest and the well plate is incubated. Following incubation, the wells are evaluated for presence or absence of the test organism. These data provide useful information related to the minimum inhibitory concentration or minimum bactericidal concentration of a product.