Microbe isolation

Plating out microbial cultures

When you are working with microorganisms it is often necessary to conduct experiments in which the cells have the same genetic background. Asexual reproduction of single-celled organisms mostly ensures that all offspring derived from a single cell have the same genetic makeup, however, sometimes random mutations can still occur. This is especially important for molecular cloning and for microbe identification.

Choosing colonies for culture

When we are checking a plate after growing microorganisms on its surface, sometimes we find colonies that are different stand out as different due to their color shape or size. When choosing which to remove for further culture, we should always choose a single colony that is representative of the majority of the plate. Any variations might indicate mutation or contamination by a foreign organism.

The two most commonly used methods are: