Mueller Hinton Agar is an in vitro diagnostic medical device used to determine the susceptibility of microorganisms to antimicrobial agents, such as antibiotics and sulfonamides. It is a culture medium for Antimicrobial Susceptibility Testing (AST) by disc diffusion of common, aerobic, rapidly growing bacteria, following the Bauer-Kirby method, as standardized by the Clinical and Laboratory Standards Institute (CLSI) and Ericsson, and is used primarily for isolates from clinical specimens.