Chopped Meat Carbohydrate Broth, PR II (pre-reduced medium in Hungate tubes) is a general-purpose medium for the enrichment and cultivation of anaerobic microorganisms, particularly obligate anaerobes.
- Anaerobic nitrogen and hydrogen atmosphere
- Packaged under oxygen-free conditions
- Meat pellets and enzymatic digest of casein provide nitrogen
- Yeast extract provides B-complex vitamins
- Glucose is a source of energy
- Phosphate maintains the pH of the medium
The reducing action of the meat particles and L-cysteine binds molecular oxygen. The reducing agents are required to maintain a low Eh. Resazurin is an oxidation-reduction indicator used to detect changes in the Eh of the medium. The medium remains colorless if the Eh remains low; increased oxidation causes the medium to become pink.
