A
microbiological culture, or
microbial culture, is a method of multiplying
microbial organisms by letting them reproduce in predetermined
culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested, or both. 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. For example, a
throat culture is taken by scraping the lining of tissue in the back of the throat and blotting the sample into a medium to be able to screen for harmful microorganisms, such as
Streptococcus pyogenes, the causative agent of strep throat. Furthermore, the term culture is more generally used informally to refer to "selectively growing" a specific kind of microorganism in the lab.