Chromogenic Medium, Dehydrated, 5.2 g

Conventional procedures for verification of fecal coliforms such as E. coli when fecal contamination is suspected are often laborious and time-consuming. A simple method used to detect and differentiate between E. coli and other coliform bacteria is the use of an indicator for enzymes produced by specific bacteria. This agar medium contains chromogenic substrates that are linked to a dye. When enzymes produced by E. coli act on certain substrates, the reaction produces a pink color in the plated bacterial colonies. A second substrate produces a blue color when acted on by enzymes produced by other coliform bacteria. Total coliforms may be determined by finding the sum of the number of pink colonies and the number of blue colonies. (E. coli is a member of the coliform group.) Organisms other than coliforms or E. coli will appear as white or colorless colonies in the medium. The medium contains peptones to provide essential growth substances and trace ingredients. Selective agents in the medium inhibit the growth of Gram-positive and other noncoliform bacteria that may be present in the water sample.

Use this medium to refill Carolina EcoKits®: Coliform Contamination (item #187220).

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