Description : The need to add NaCl to agar media to ensure accuracy of results when testing staphylococci with oxacillin was investigated. Each lot of Mueller Hinton Agar and Mueller Hinton II Agar has been tested according to, and meets the acceptance limits of, the current M6 protocol published by the CLSI. Mueller Hinton Agar is recommended for antimicrobial disc diffusion susceptibility testing of common, rapidly growing bacteria by the Bauer-Kirby method,1-3 as standardized by the Clinical and Labora