[Standardization of the nutrient medium for determining the biological activity of a number of antibiotics by the diffusion-in-agar method]. / Unifikatsiia pitatel'noi sredy dlia opredeleniia biologicheskoi aktivnosti riada antibiotikov metodom diffuzii v agar.

The possibility of using 2 variants of a unified nutrient medium containing no Hottinger's broth for determination of the biological activity of a large number of antibacterial antibiotics was shown. The medium provided satisfactory reproducibility of the results. It contained yeast extract as a source of nitrogen. The medium was selected with the method of the fractional factor experiment. Clear inhibition growth zones and the slope of the dose-response curve were used as the criteria for estimation of the optimal medium. The described nutrient medium allowed a 2-time increase in the sensitivity of the method used for determination of the biological activity of neomycin, monomycin, streptomycin, oxytetracycline, chlortetracycline and erythromycin.