Resazurin is the oxidation indicator. In the oxidized state, resazurin turns pink. In the reduced state resazurin is colorless. Dextrose is included in this formula to enhance organism growth. Sodium Chloride maintains the osmotic balance of the medium. The requirement for a sealed environment is eliminated with the addition of Agar, which retards dispersion of CO2, diffusion of oxygen, and reducing substances.9