Middlebrook 7H9 Broth is recommended for use in qualitative procedures for the isolation and cultivation of Mycobacterium species.

• Glycerol, albumin, and dextrose support growth
• Sodium citrate holds certain inorganic cations in solution
• Ammonium sulfate supplies a nitrogen source
• Catalase minimizes toxic effects

Middlebrook media consists of many inorganic salts which help in the growth of Mycobacteria. Mycobacteria grow more rapidly in broth media; therefore, primary isolation of all specimens can be done in Middlebrook 7H9 Broth Base.