E test (AB Biodisk NA, Piscataway, NJ)
Click picture to enlarge. Close window to return

The E test is a recently developed quantitative method of determining the minimum inhibitory concentration (MIC), wherein a plastic strip with a calibrated gradient of antimicrobial is placed upon an agar plate with a standardized concentration of the microbial isolate. The MIC is read directly off the strip where the colonies cross the calibrated strip. In this example, the colonies cross the strip at a value of 0.94 mcg/ml.