Tetrathionate Broth Base is used as a selective enrichment medium for the isolation of Salmonella from feces, urine, foods, and other materials of sanitary importance.

• Peptones provide nitrogen, vitamins, amino acids, and carbon
• Oxgall inhibits Gram-positive microorganisms
• Calcium carbonate neutralizes and absorbs toxic metabolites

Tetrathionate, which is formed in the medium by the addition of the iodine-iodide solution, inhibits the normal intestinal flora of fecal specimens.