Dextrose Tryptone Agar is used for cultivating thermophilic "flat-sour" microorganisms associated with food spoilage.

• Peptones provide carbon and nitrogen sources
• Dextrose is the carbohydrate source
• Bromcresol purple is the pH indicator
• Agar is the solidifying agent

Dextrose Tryptone Agar can also be used to isolate other food from spoilage bacteria; mesophilic aerobic spore formers in the genera Bacillus and Sporolactobacillus and thermophilic flat sour spore formers such as B. stearothermophilus.