What is the medium? species of medium
mediumIt is a substrate artificially prepared from various nutrients suitable for bacterial growth and reproduction. Collected and sorted out by the National Standard Product Network.mediumSynthetic medium, nutrient medium, identification medium, selection medium and anaerobic medium. According to the physical form of the medium, it is divided into three categories: solid, semi-solid and liquid medium. According to the type of bacteria and the purpose of culture, different media can be used.
Classification according to knowledge of the composition of the medium
Natural medium: refers to a type of medium made from animals, plants or microorganisms, including their extracts, such as beef paste peptone medium, wort medium, etc.
Combination medium: also known as synthetic medium or comprehensive medium, is a type of medium that is precisely designed according to the nutritional requirements of microorganisms and formulated with a variety of high-purity chemical reagents, such as glucose ammonium salt medium, starch nitrate medium, etc.
Semi-combination medium: refers to a type of medium that is mainly prepared with chemical reagents and also adds some or some natural ingredients. For example, potato sucrose medium.
Classification according to the physical state of the appearance of the medium
Liquid medium: a type of medium that is liquid.
Solid medium: a type of solid medium with solid appearance. According to its properties, it can be divided into solidified medium, non-reversible solidified medium, natural solid medium, and filter membrane.
Semi-solid medium: refers to a semi-solid medium prepared by adding a small amount of coagulant to the liquid medium.
Dehydrated medium: also known as prefabricated dry medium, refers to a commercial medium containing all ingredients except moisture.
Classification of microorganisms according to their function in culture medium
Selective medium: a type of medium designed according to the specific nutritional requirements of a microorganism or its resistance to certain chemical and physical factors. It has the function of turning the inferior bacteria in the mixed bacteria into the dominant bacteria. It is widely used in Identification medium: a type of medium that adds an indicator that can react with the colorless metabolites of the target bacteria in color, so that the target bacterial colony can be easily identified from the similar colony only by the naked eye. For example, eosin methylene blue lactose medium (EMB).
How to use the medium:
1. Tear along the notch on the side of the aluminum-plastic bag or cut the sealing opening with scissors, and take out the gas bag.
2. Immediately put the gas production bag into the 2.5L anaerobic culture bag containing the petri dish and seal the culture bag. At this time, the gas production bag will absorb the O2 in the culture bag and generate CO2 at the same time.
3. Under normal circumstances, within 60 minutes, oxygen is fully absorbed, generating approximately 20 to 21% carbon dioxide.
