Rogosa Agar (also known as RMW Agar) is a medium for the selective isolation and enumeration of lactobacilli belonging to the oral and intestinal flora (feces and mouthwash), as well as to foods such as milk and meat. The low pH and high concentrations of acetate effectively suppress other bacterial flora allowing the lactobacilli to grow. The pH of the medium is adjusted to 5.5 by the addition of glacial acetic acid. Nutritional components include pancreatic digestion of casein, yeast extract and dextrose. Manganese sulfate, magnesium sulfate, ferrous sulfate and polysorbate 80 provide essential ions and growth factors for the cultivation of a variety of lactobacilli. The different salts contained in this medium make it unsuitable for the isolation of dairy lactobacilli such as L. lactis, L. bulgaricus and L. helveticus.