Trypticase soy agar or tryptic soy agar or tryptone soya agar (TSA)
Is a widely used medium containing two peptones which support the growth of a wide variety of organisms, even that of very fastidious ones such as Neisseria, Listeria, Brucella ,etc. It is frequently used for routine diagnostic purposes due to its reliability and its easily reproducible results. The following list includes some of its most common applications:The medium provides, with added blood, perfectly defined haemolysis zones, while preventing the lysis of erythrocytes due to its sodium chloride content. It can be used for the preparation of an exceptionally nutrient `chocolate ́ agar, thanks to the richness of its peptones. In a reducing environment or with a CO₂ enriched atmosphere, it provides an excellent medium for the isolation of Brucella and Neisseria. It may be made selective by using additives.Most streptococci grow in this medium though clear differences can be observed from one species to another.Several tests for the differentiation and identification of staphylococci can be performed on this medium, provided suitable additives are used.Yeast, particularly Candida species, can grow in this medium forming very characteristic colonies.Chromogenic pseudomonas frequently produce pigmentation on TSA and are therefore easily recognized.Avast bibliography documents its applications in the food industry.It has been frequently used in the Health 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.A balanced and high nutrient value together with a lack of fermentable carbohydrates make this medium ideal for maintaining bacterial strains.If it is desired to use as an alternative medium in confirming the presumptive Legionella colonies isolated on the BCYE medium, the pH of the TSA must be adjusted so that after sterilization it is 6.8±0.2 at 25°C.