Micrology Laboratories Coliscan Easygel Media incorporates a patented combination of color-producing chemicals and nutrients that mark coliforms and E. coli in differing colors for easy identification and isolation. This means that a test sample of water or other material may be added to the medium, and coliform bacteria will grow as pink-magenta colonies while E. coli will grow as purple-blue colonies. Other bacterial types will grow as non-colored colonies.

There are two approaches to the Coliscan method: Coliscan EasyGel and Coliscan-MF.

Coliscan Easygel is ideal when a sample size of 1-5mL is appropriate, such as samples where there is generally a sizable population of coliforms and/or E. coli. The samples can be added directly into the bottle of Coliscan Easygel, swirled, pouring into a pretreated petri dish and incubated. Incubation temperature is not critical and under warm conditions (32° - 37°C) the results can be read in 24-28 hours.

Coliscan-MF is used with membrane filters and it allows the use of much larger test samples of any filterable liquid. This method is commonly used with samples that contain a low level of coliforms or E.coli. With this approach, the sample is filtered through a membrane filter. After the bacteria are collected on the surface of the filter, it is placed on a pad saturated with Coliscan-MF liquid medium in a petri dish. The colonies grow on the surface of the filter and are then counted.