m-Enterococcus Agar is used for the selective isolation and enumeration of Enterococci in water, food and other materials. Tryptose provides the nitrogen, minerals and amino acids in this medium. Yeast Extract is a source of B-complex vitamins and trace elements. Dextrose is the carbon source. Dipotassium Phosphate serves as pH buffer. Sodium Azide suppresses the growth of Gram-negative bacteria. 2,3,5-Triphenyl Tetrazolium Chloride is a dye that is reduced to insoluble formazan upon uptake by the bacterial cell, resulting in the formation of red colonies. Agar is used as a gelifying agent.