Zone of Inhibition

∞ generated and posted on 2016.02.20 ∞

Area around a disk that has been impregnated with an antimicrobial substance, within which specific microorganisms are unable to grow.

Zones of inhibition are seen with disk-diffusion methods of determining disinfectant or antibiotic sensitivity.

Zone of Inhibition

Figure legend: Shown are zones of inhibition created in the course of a disk-diffusion assay. The zones are areas lacking in visible bacterial growth and form in the course of bacterial lawn maturation from a low-cell-density, non-turbid growth to growth so turbid that objects are not visible through it, except for those areas in which bacterial growth is lacking, i.e., the zones of inhibition. The size of these zones of inhibition in turn are a function of the susceptibility of the lawn bacteria to the antibacterial impregnated into the filter-paper disks.