Description

Digested Soy Casein Agar is a widely used medium, which supports the growth of a wide variety of organisms, even the most demanding ones such as Neisseria, Listeria, Brucella, etc. The blood-added medium provides well-defined areas of hemolysis while preventing lysis. of erythrocytes due to their sodium chloride content. It has been used frequently in the healthcare industry to produce antigens, toxins, etc. Its simple and inhibitor-free composition makes it suitable for the detection of antimicrobial agents in food and other products. Several pharmacopeias recommend tryptone soy agar as a sterility test medium (1, 2).

Tryptone Soya Agar is compliant with USP (1) and is used in microbial limit testing and effective testing of antimicrobial preservatives. Gunn et al (3) used this medium for the growth of fastidious organisms and the study of the hemolytic reaction after the addition of 5% v / v blood. The combination of pancreatic digestion of casein and papain digestion of soybean meal makes this medium nutritious by providing amino acids and long-chain peptides for the growth of microorganisms. Sodium chloride maintains osmotic balance.

Digested Soy Casein Agar does not contain growth factors X and V. It can be conveniently used to determine the requirements of these growth factors by Haemophilus isolates by adding factor X (DD020), factor V (DD021), and factor from factor X + V discs (DD022) to inoculated TSA plates (4).

Directions: Suspend 40 grams in 1000 ml of distilled water. Heat to a boil to dissolve the medium completely. Sterilize by autoclaving at a pressure of 15 pounds (121 ° C) for 15 minutes. If desired, aseptically add 5% v / v defibrinated blood to medium previously cooled to 45-50 ° C for culture. Mix well and pour into sterile Petri dishes.