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Content Authors: Level:
Marilena Ioannou and Malgorzata Rekas General interest
Click here for: Animation of measuring ZOI
Click here for: Video of measuring ZOI on YouTube
Microbiology OER Description:
These OERs are microbiology resources explaining the fundamental principle of how to measure zones of inhibition or ZOI. This is a simple microbiology screening test to assess the effect of antibacterial agents on bacterial growth. Bugs are grown on agar plates and a round disc containing a known concentration of antibiotic is placed. If the bacteria is susceptible to the antibiotic, then there will be an area where it does not grow.
In an experimental situation, measuring the dimensions of the zone of inhibited growth can help compare the effects of different antibiotics and different concentrations.