Determination of the ID50 values of antibacterial agents in agar.
- 1 January 1978
- journal article
- research article
- Published by Japan Antibiotics Research Association in The Journal of Antibiotics
- Vol. 31 (12) , 1299-1303
- https://doi.org/10.7164/antibiotics.31.1299
Abstract
Microorganisms were plated on agar plates containing various concentrations of an antimicrobial drug, and inhibition of growth was determined at each drug concentration. The ID50 [median inhibitory concentration] value and the gradient of the line were calculated by the least squares method. When 200-800 bacterial cells were inoculated on an agar plate, growth inhibition corresponded linearly with the log concentration of a drug within the range of 5-95% inhibition. The ID50 value and the gradient obtained were reproducible and reliable using microorganisms at a stationary phase of growth with all tested bacterial species and all tested antimicrobial agents. The ID50 values of drugs were more reproducible and may be more reliable than the MIC (minimum inhibitory concentration) values of the drugs.This publication has 0 references indexed in Scilit: