ABSTRACT
Microbiological examinations used a vast variety of culture media, the formulation of which varies as a function of the microorganisms that will be cultivated and the tests for which they are intended. The ingredients used to formulate culture media are generally commercially available in dehydrated form, and include sources of nutrients, selective agents, differential agents, reducing agents, buffering agents, chromogenic and fluorogenic substrates and agar. The water used to prepare media and reagents must be purified. Storage should be done in flasks made of inert materials, such as neutral glass or polyethylene. The main nutrient sources used in the formulation of culture media are peptones, meat extract, yeast extract, malt extract, carbohydrates, minerals and the essential metals. Peptone is the generic name of products generated by acid or enzyme hydrolysis of proteins of animal or vegetal. The carbohydrates, particularly glucose, are a source of carbon and energy used by most microorganisms.
