Radial diffusion assay

The radial diffusion assay is a laboratory technique used to measure the activity of antimicrobial substances, like antibiotics. In this test, a gel containing bacteria is prepared, and small amounts of the substance being tested are placed in the center of each well. As the substance diffuses outward through the gel, it inhibits bacterial growth around it. The size of the clear zone, or "halo," indicates the potency of the antimicrobial. Larger halos mean stronger activity. This method helps researchers evaluate how effective different agents are against specific bacteria in a straightforward way.