Tryptic Soy Agar

Sterilize in an autoclave between 118 and 121°C at a pressure of no more than 15 lbs. for 15 minutes. In the case of large volume preparation, increase the time of sterilization but not the temperature or pressure. Cool and pour into Petri dishes. For hemolytic studies, add 5 to 10% sheep or rabbit blood.

In Tryptic Soy Agar, Casein peptone and Soya peptone provide nitrogen, vitamins and minerals. The natural sugars from Soya peptone promote bacterial growth. Sodium chloride is for the osmotic balance.

Tryptic Soy Agar is used for the isolation and cultivation of fastidious and non-fastidious micro-organisms. It supports the abundant growth of fastidious organisms such as Pneumococci, Streptococci, Neisserias, etc. Since it lacks carbohydrates, it is very useful in the study of hemolytic reactions and also in the preparation of chocolate agar. Also, it may be used for sterility testing. It can be used with or without blood supplement. It is used as precultivation medium and enumeration (E. coli) acc. to membrane-filter technique. As it does not contain the X and V factors, it is suitable for identification of Haemophilus sp. by adding X (Hemin) and V (DPN) factors strips.

Tryptic Soy Agar is a medium very rich in nutrients for "general use" in microbiological laboratories. Containing two peptones obtained by enzymatic hydrolysis of casein and soy protein, this medium supports the growth of a great variety of microorganisms, including fastidious aerobes and anaerobes. If desired, antibiotics can easily be incorporated as well as other supplements or inhibitory agents. A short list of microorganisms that grow on this medium are the following: Streptococcus, Neisseria, Brucella, Corynebacterium, Listeria, Pasteurella, Vibrio, Haemophilus vaginals, Candida, etc.

Tryptone Soya Agar is recommended as a reference medium when testing selective media, to measure the degree of inhibition.