Description : Tryptic Soy Agar is used for isolating and cultivating fastidious microorganisms and, with blood, in determining hemolytic reactions. Tryptic soy agar (TSA) inoculated with Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli demonstrating growth of all three organisms. TSA is a general purpose medium that will allow for the growth of all three organisms. Filled in 50mm diameter petridishes.