National Cancer Institute (source definition)
Epsilometry
A method to determine microbial susceptibility to antibiotics in which a plastic strip impregnated with the antibiotic of interest is placed on an agar plate that has been inoculated with bacteria. The antibiotic diffuses from the strip producing a concentration gradient of drug on the agar. The point at which the elliptical shaped area of growth inhibition meets the strip is the minimum inhibitory concentration of the drug of interest.
Review and references
Automated source check (NCI definition)
2026-10-20
2026-10-20
professional use
What it is
A method to determine microbial susceptibility to antibiotics in which a plastic strip impregnated with the antibiotic of interest is placed on an agar plate that has been inoculated with bacteria. The antibiotic diffuses from the strip producing a concentration gradient of drug on the agar. The point at which the elliptical shaped area of growth inhibition meets the strip is the minimum inhibitory concentration of the drug of interest.
Source: National Cancer Institute, NCI Thesaurus 26.09d, C85596. NCI definition, reproduced without modification under CC BY 4.0.
Source identity and definition checked automatically on 2026-10-20. No individual clinical interpretation or human reviewer is asserted.
Compliance note
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.