Trypticase soy agar e Caseína

Trypticase soy agar is a bacterial growth medium.

TSA is a general purpose medium , providing enough nutrients to allow for a wide variety of microorganisms to grow. It is used for a wide range of applications including; culture storage, enumeration (counting), isolation of pure cultures or simply general culture. e.g. Tryptocase Soy Agar (TSA) Tryptocase Soy Broth (TSB) Nutrient Agar

The medium contains enzymatic digests of casein and soybean meal which provides amino acids and other nitrogenous substances making it a nutritious medium for a variety of organisms.Glucose is the energy source. Sodium chloride maintains the osmotic equilibrium, while dipotassium phosphate acts as buffer to maintain pH. Agar extracted from any number of organisms is used as a gelling agent.

The medium may be supplemented with blood to facilitate the growth of more fastidious bacteria or antimicrobial agents to permit the selection of various microbial groups from pure flora. As with any media, minor changes may be made to suit specific circumstances. TSA is frequently the base media of other agar plate type, i.e. blood agar plates (BAP) are made by enriching TSA plates with blood

One liter of the agar contains:^[1]

• 15 g Tryptone
• 5 g Soytone - enzymatic digest of soybean meal
• 5 g Sodium Chloride
• 15 g Agar

Casein (/ˈkeɪs.ɪn/ or /ˈkeɪˌsiːn/, from Latin caseus, "cheese") is the name for a family of related phosphoproteins (αS1, αS2, β, κ). These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 20% and 45% of the proteins in human milk.^[1] Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive, to a binder for safety matches.^[2] As a food source, casein supplies amino acids, carbohydrates, and the two inorganic elements calcium and phosphorus.^[3]

Ágar e Agarose

Agar (pronounced /ˈɑːɡər/, "ah-gər") or agar-agar (/ˈɑːɡərˈɑːɡər/, "ah-gər-ah-gər") is a gelatinous substance, obtained from algae and discovered in 1658 by Minora Tanzaemon in Japan, where it is called Kanten, and is used traditionally in some confectionaries.

Agar is derived from the polysaccharide agarose, which forms the supporting structure in the cell walls of certain species of algae, and which is released on boiling. These algae are known as agarophytes and belong to the Rhodophyta (red algae) phylum .^[1][2] Agar is actually the resulting mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin.^[3]

Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium for microbiological work. Agar (agar-agar) can be used as a laxative, an appetite suppressant, vegetarian gelatinsubstitute, a thickener for soups, in fruit preserves, ice cream, and other desserts, as a clarifying agent in brewing, and for sizing paper and fabrics.^[4]

An agarose is a polysaccharide polymer material, generally extracted from seaweed. Agarose is a linear polymer made up of the repeating unit of agarobiose, which is a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose.^[1] Agarose is one of the two principal components ofagar, and is purified from agar by removing agar's other component, agaropectin.^[2]

Agarose is frequently used in molecular biology for the separation of large molecules, especially DNA, by electrophoresis. Slabs of agarose gels (usually 0.7 - 2%) for electrophoresis are readily prepared by pouring the warm, liquid solution into a mold. A wide range of different agaroses, of varying molecular weights and properties are commercially available for this purpose.