Triple Sugar Iron Agar (TSI Agar) is used for the differentiation of Gram-negative enteric bacilli based on carbohydrate fermentation and the production of hydrogen sulfide.

• Contains three sugar: dextrose, lactose, and sucrose
• Phenol red for detecting carbohydrate fermentation
• Ferrous ammonium sulfate detects hydrogen sulfide production
• Dehydrated appearance: Pink, free-flowing

The addition of sucrose to the double sugar formulation of Kligler Iron Agar increased the sensitivity of the medium by facilitating the detection of sucrose-fermenting bacilli, as well as lactose and/or dextrose fermenters.