Russel medium is used for the differentiation of enterobacteria on the ability to ferment lactose or glucose. According to the analysis, the bacteria are divided into three groups: lactose fermenting, glucosaminidase and bacteria, not fermenting carbohydrates. Analyze samples after 19-20 hours, because earlier they can be incorrect, because of a staged fermentation medium components. Be sure to leave one control vial (original color is green).