Media biology relates to designing of a gel or a liquid which tends to help in the growth of cells or microorganisms and there are various types of media biology but there are two major types of it. In one, specialized cells are taken from animals or plants and these are then used for growing microorganisms, the other types of media biology is the one where the growth of microorganisms happens through nutrient broths.
Thus, one can divide the types of media biology into three categories and these are nutrient, selective and differential. Nutrient media biology is the most common one, and is able to support the growth of almost all of the microorganisms. Since, it supports a wide range of organisms; this type becomes the non selective type of media biology. The various examples of nutrient media biology are blood agar, soy agar and nutrient agar. Most of the time, these agars are mixed with a liquid based medium and then with the help of a sterile dispenser are poured into a petri dish, so that these can get solidified. The microbes can then be easily cultured as the agar plates provide them a solid medium. As they are able to remain solid, only a few amounts of bacteria tend to decompose.
Selective media is that types of media biology where only a selected set of microorganisms are able to grow and at the same time they prohibit the growth of other set of microorganisms. One example of these types of media biology can be of a microorganism which might resist a certain type of antibiotic, so this organism can be added to such a group or to a medium where it can prohibit the growth of those set of microorganisms which are not resistant to that antibiotic. The examples of selective media can be mannitol salt agar, EMB agar, amongst others.
Differential media is that type where one is able to differentiate between various types of microorganisms on the basis of their characteristic which they show when they are being grown on a particular type of medium. These different characteristics are easily visible and one is able to differentiate between these microorganisms easily. These are mainly used for detection of new types of organisms. The examples of differential media are eosin methylene blue agar, MacConkey agar, amongst others.
Apart from these three major types of media biology, there is another category of media biology where the microorganisms tend to show characteristics of both selective as well as differential media biology. Such type of organisms are very helpful tools for diagnosis when one is trying to study environmental as well as medical setting. Blood agar is a microorganism which is nutritive but at the same time is also differential. The differential property of this organism is called hemolysis. Hemolysis is the property which tends to destroy RBC’s, or erythrocytes.
All these types of media biology are very helpful in the growth of various types of microorganisms and that too in a sterilized manner.