In bacterial colony assays, the patterns are formed within culture media that has been inoculated with bacterial cells. This allows the cells to reproduce and form bacterial colonies within and/or on the surface of the medium. When the colonies are sufficiently large, they are usually visible to the naked eye, which allows researchers to determine the number of colonies formed. In addition, various visual characteristics of the colonies, such as shape, size, pigmentation, and opacity, can be used to help determine the type of bacterium present.
(See Biology of Microorganisms, 8th Edition, M. T. Madigan, J. M. Martinko and J. Parker, © 1997, Prentice Hall, pp 24-25, 156-157; Bacteria in Biology, Biotechnology and Medicine, Third Edition, Paul Singleton, © 1995, John Wiley & Sons, Inc. pp. 37-38; Microorganisms in Our World, Ronald M. Atlas, © 1995, Mosby-Year Book, Inc. pp. 82-83, 292-294)
In bacterial colony counting, the colonies formed are enumerated, either manually or using automated image analysis techniques. Their visual characteristics can also be evaluated.
See also: Assays
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