Determining the morphology of a single colony growing on the surface of a plate culture can be an important tool in the description and identification of microorganisms. On solid media, a colony is theoretically derived from a single cell. If well-separated from other colonies, a colony will have a characteristic shape (both in elevation and margin), size, color and consistency. Observation is often made with the naked eye, but dissecting microscopes are also used. The characteristics defined by a colony’s morphology may be used at a superficial level to distinguish between types of microorganisms. For example, there are differences in morphologies when rough and smooth colonies of Streptococcus pneumonieae are examined. Another comparison can be made when describing pigmented colonies.
