Tryptic Soy Agar

Tryptic Soy Agar is used for the cultivation of a wide variety of microorganisms in a laboratory setting. Tryptic Soy Agar is not intended for use in the diagnosis of disease or other conditions in humans. Tryptic Soy Agar conforms to Harmonized USP/EP/JP Requirements.

In 1955, Leavitt et al. discovered Tryptic Soy Agar (TSA) facilitated vigorous growth of aerobic and anaerobic microorganisms. TSA, a general purpose medium, is commonly referred to as Soybean-Casein Digest Agar USP 23. TSA is a nutritious base, and a variety of supplements can be added to enhance this medium. The addition of 5% sterile, defibrinated sheep, horse, or rabbit blood provides an excellent non-selective medium, used to determine hemolytic reactions of bacteria. TSA supplemented with lecithin and Tween 80 is widely used in environmental monitoring.

TSA is recommended in multiple water & wastewater applications, and numerous standard methods for food testing. This medium also conforms to Harmonized United States Pharmacopoeia (USP), European Pharmacopoeia (EU), and Japanese Pharmacopoeia (JP). Clinically, TSA is used in the differentiation of Haemophilus species (the X and V factors are omitted from this medium), and widely used for blood cultures. TSA is commonly used as a maintenance medium for culture collections, and testing bacterial contaminants in cosmetics.


Formula Liter
Enzymatic Digest of Casein 15 g
Enzymatic Digest of Soybean Meal 5 g
Sodium Chloride 5 g
Agar 15 g

Final pH: 7.3 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Suspend 40 g of the medium in one liter of purified water.
  2. Heat with frequent agitation and boil for one minute to completely dissolve the medium.
  3. Autoclave at 121°C for 15 minutes.
  4. Optional: Prepare 5 to 10% blood agar by adding appropriate volume of sterile defibrinated blood to melted sterile agar medium, cooled to 45 – 50°C.

Order Details

Product # Product Description
7100A Tryptic Soy Agar, 500 g
7100T Tryptic Soy Agar, 5 kg