For sterility testing of biological products. ALTERNATIVE THIOGLYCOLLATE MEDIUM (NIH THIOGLYCOLLATE MEDIUM) (VEG.) is used for sterility testing of biological products. The media is also used for sterility testing of antibiotics, biologicals and foods and also for determining the phenol coefficient and sporicidal effect of disinfectants. However, it is intended for the examination of clear liquid or water-soluble materials. Fluid Thioglycollate Medium is also routinely used to check the sterility of stored blood in blood banks. The medium contains Vegetable hydrolysate and Yeast extract those provide the nitrogen and essential growth enhancers necessary for bacterial multiplication. Sodium thioglycollate and L- Cystine acts as a reducing agent which maintains a low oxygen tension by removing molecular oxygen from the environment. Dextrose is a fermentable energy source. On incubation period of 30 - 350 C for 48- 72 hours shown luxuriant growth in all the culture strains tested. Sodium chloride helps maintaining the osmotic balance. The NIH Thioglycollate Medium without Indicator is suitable for diagnostic work of viscous products because the lack of indicator avoids possible toxicity to organisms.