|
A mucilaginous carbohydrate that is used in the form of a gel as a microbiological supporting medium. It is obtained from certain red algae, notably Gelidium species. The gel is produced by dissolving agar crystals in boiling water and then allowing the mixture to cool. It may be sterilized by placing in an autoclave. A nutrient agar gel has various nutrients added to it. Agar is widely used because it is resistant to attack by almost all microorganisms, and, as it does not melt until 100°C, incubation of the selected culture can take place at high temperatures. When agar is used in a Petri dish it is known as an agar plate.
|
