EMB Broth

EMB Broth is recommeded for differentiation of Gram-negative enteric bacteria from clinical & non-clinical specimens. Methylene blue and Eosin-Y inhibits gram-positive bacteria and also acts as differential indicators. Escherichia coli grows luxuriantlly on the media and shows purple with green metallic sheen since they uptake the complex methylene blue-eosin dye. Klebsiella aerogenes and Klebsiella pneumoniae shows good growth and forms pink colored colony on the media. Nonfermenters such as Shigella probably raise the pH of surrounding medium by oxidative deamination of protein, which solubilizes the methylene blue-eosin complex resulting in colourless broth