The nutritional composition of Trypticase Soy Agar has made it a popular medium, both unsupplemented and as a base for media containing blood. Tryptic Soy Agar with 5% sheep blood is extensively used for the recovery and cultivation of fastidious microbial species and for the determination of hemolytic reactions which are important differentiating characteristics for bacteria, especially Streptococcus species. The absence of reducing sugars and carbohydrates allows the hemolysis to occur without hindrance. Medium is recommended for use in the cultivation of microorganisms from environmental surfaces. They are used primarily to monitor microbial contamination, for enumeration of microbial colonies growing on a variety of surfaces, and to assist in determining surface sanitation.