Phenol Red Sorbitol Broth is used for sorbitol fermentation studies of microorganisms.to determine the fermentation reaction of carbohydrates for the differentiation of microorganisms, with various carbohydrates serves as a differential medium by aiding in differentiation of various species and genera by their ability to ferment the specific carbohydrate, with the production of acid or acid and gas. It is used to study sorbitol fermentation in various bacteria.