Thermo Scientific™ Middlebrook 7H9 Broth w/Polysorbate 80

Description

• Differentiate Mycobacterium species based on their ability to reduce potassium tellurite using Thermo Scientific™ Remel™ Middlebrook 7H9 Broth w/Polysorbate 80 (Tellurite Reduction Medium)
• Middlebrook and Cohn developed Middlebrook 7H9 Broth in 1958 to cultivate mycobacteria 1
• Kilburn et al
• described the differential identification of mycobacteria using the tellurite reduction test 2
• They reported that all mycobacteria growing actively on a solid medium rapidly reduced a solution of tellurite salt used to flood the plate
• Use Middlebrook 7H9 Broth w/Polysorbate 80 for differentiation of Mycobacterium species based on their ability to reduce potassium tellurite
• Ready-to-use – Convenience of prepared media
• Easy-to-interpret – Based on tellurite reduction
• Middlebrook 7H9 Broth w/Polysorbate 80 contains inorganic compounds that supply potassium, sulfur, magnesium, and phosphorus necessary for the growth of mycobacteria
• Inorganic copper, iron, zinc, and calcium are growth stimulators
• Sodium citrate holds certain inorganic cations in solutions
• Ammonium sulfate is a source of nitrogen and dextrose is a source of carbon
• Albumin binds to the free fatty acids which may be toxic to Mycobacterium species and acts as a protective agent
• Catalase destroys toxic peroxides which may be present in the medium and catalyzes the reaction of iron with molecular oxygen
• Biotin is required for carboxylation and decarboxylation reactions and pyridoxine is a precursor of enzymatic activity
• Polysorbate 80 is a wetting agent that encourages more homogenous growth.