Used in microbiology for detecting bacterial fermentation of carbohydrates (including gas production indicated by bubbles or cracks) and production of hydrogen sulfide. Helps differentiate members of the Enterobacteriaceae family based on their metabolic activities. The medium allows observation of color changes indicating acid or alkaline products, and black precipitate formation when H₂S is produced. Commonly used in clinical labs for stool sample analysis and identification of pathogenic gut bacteria. Provides a quick and reliable method for preliminary classification of gram-negative rods.