Microbiological culture
Microbial cultures are foundational and basic diagnostic methods used as research tools in molecular biology.
It is one of the primary diagnostic methods of microbiology and used as a tool to determine the cause of infectious disease by letting the agent multiply in a predetermined medium.
[1] Furthermore, the term culture is more generally used informally to refer to "selectively growing" a specific kind of microorganism in the lab.
A pure (or axenic) culture is a population of cells or multicellular organisms growing in the absence of other species or types.
[3] Koch's method of using a flat plate for his solid media was replaced by Julius Richard Petri's round box in 1887.
[2] Since these foundational inventions, a diverse array of media and methods have evolved to help scientists grow, identify, and purify cultures of microorganisms.
[6] Microbiological cultures can be grown in petri dishes of differing sizes that have a thin layer of agar-based growth medium.
Once the growth medium in the petri dish is inoculated with the desired bacteria, the plates are incubated at the optimal temperature for the growing of the selected bacteria (for example, usually at 37 degrees Celsius, or the human body temperature, for cultures from humans or animals, or lower for environmental cultures).
After the desired level of growth is achieved, agar plates can be stored upside down in a refrigerator for an extended period of time to keep bacteria for future experiments.
When the selected antibiotic is added to the agar, only bacterial cells containing the gene insert conferring resistance will be able to grow.
They have advantages over agar plates since they are cost effective and their operation does not require expertise or laboratory environment, which enable them to be used at the point-of-care.
An example of this is MacConkey agar (MAC), which reveals lactose-fermenting bacteria through a pH indicator that changes color when acids are produced from fermentation.
The panel will be incubated in a machine, which subsequently analyses each well with a light-based method such as colorimetry, turbidimetry, or fluorometry.
growing at temperatures of 50 to 70 degrees C, low acyl clarified gellan gum has been proven to be the preferred gelling agent comparing to agar for the counting or isolation or both of the above thermophilic bacteria.
