TAT (Trypton-Azolectin-Tween) Broth is a non-selective liquid medium used for the detection of microorganisms in cosmetics, topical drugs and viscous or gelatinous substances (such as ointments and salves). It is used for the isolation and culture of Gram-negative bacteria. Topical cosmetics and pharmaceuticals are easily subject to contamination during the manufacturing process and during their continued use by consumers. Therefore, these products contain preservatives for self-sterilization against vegetative bacteria, yeasts and molds.

The pancreatic digestion of casein provides nitrogen, vitamins, minerals and amino acids essential for growth. The high concentration of casein peptone allows the development of spores of all microorganisms, including damaged microorganisms. Soy lecithin (azolectin) and polysorbate neutralize preservatives included in cosmetic and pharmaceutical products, allowing the growth of microorganisms.