what is mic

MIC stands for Minimum Inhibitory Concentration, which is the lowest concentration of a chemical, usually a drug, that prevents visible in vitro growth of bacteria or fungi. MIC testing is performed in both diagnostic and drug discovery laboratories. The MIC is determined by preparing a dilution series of the chemical, adding agar or broth, then inoculating with bacteria or fungi, and incubating at a suitable temperature. The value obtained is largely dependent on the susceptibility of the microorganism and the antimicrobial potency of the chemical, but other variables can affect results too. The MIC is often expressed in micrograms per milliliter (μg/mL) or milligrams per liter (mg/L) . In diagnostic labs, MIC test results are used to grade microbes as "S" (susceptible or responding to a standard dosing regimen), "I" (intermediate or requiring increased exposure) or "R" (resistant) based on agreed-upon values called breakpoints. MIC scores aid in improving outcomes for patients and preventing the evolution of drug-resistant microbial strains by identifying appropriate drugs and their effective concentrations.