Discover a New Antibiotic
MIC & MBC Definitions

Christine L.Case

MIC and MBC defined



A broth dilution test is used to determine the minimal inhibitory concentration (MIC), the lowest antibiotic concentration that prevents visible bacterial growth and the minimal bactericidal concentration (MBC). The MIC is determined by making a sequence of decreasing concentrations of the drug in a broth, which is then inoculated with the test bacteria. The wells that do not show growth (higher concentration than the MIC) can be cultured in broth free of the drug. If growth occurs in this broth, the drug was not bactericidal, and the MIC can be determined. Lab protocol.


Answers to MIC problem:

Back to MIC protocol



MIC = 1:32

MBC = 1:16