Disc diffusion assay standards

The disc diffusion assay is a laboratory method used to evaluate the effectiveness of antibiotics or antimicrobial agents against bacteria. In this test, small discs soaked with the agent are placed on a petri dish containing bacteria. As the agent diffuses into the surrounding medium, it inhibits bacterial growth, creating clear zones called inhibition zones. The size of these zones indicates how effective the agent is—the larger the zone, the more effective. Standards set specific guidelines for how to perform the test, measure zones, and interpret results to ensure consistency and accurate comparisons across different experiments.