Chromogenic Coliforms Agar

List and differentiate coliforms and Escherichia coli in water samples with Thermo Scientific ™ Oxoid ™ Chromogenic Coliform Agar in accordance with ISO 9308-1 guidelines for water quality testing. Target organisms are easy to differentiate, E. coli forms dark blue / purple colonies and pink to red coliforms. Achieve full detection in 24 hours, eliminating the need for subcultures.

Catalog number : CM1205B

Full specs

  • Shelf life: 3 years
  • Format: Powder
  • Type: Media
  • Description: Chromogenic Coliform Agar (Dehydrated)
  • Product type: Agar
  • Quantity: 500 g
  • Unit size: each

Chromogenic Coliform Agar is a fast, accurate, and efficient way to detect coliforms and E. coli during microbiological quality testing of drinking water, disinfected pool water, and treatment plant samples. The guideline, ISO 9308-1: 2014 Enumeration of Escherichia coli and coliform bacteria – Part 1: Membrane filtration method for waters with low background bacterial flora, specifies a method based on membrane filtration, subsequent cultivation on an agar medium chromogenic for coliforms and calculation of the number of target organisms in the sample. Chromogenic Coliform Agar uses specific enzymes associated with general coliforms and E. coli for differentiation.

  • The Salmon GAL chromogen, when cleaved by D-galactosidase, produces a pink to red coloration; this staining and enzyme are associated with coliforms.
  • E. coli contains D-galactosidase, which cleaves Salmon GAL; however, it also contains D-glucuronidase, which cleaves the chromogen X-glucuronide. The combination of these chromogens produces a dark blue to violet coloration associated with E. coli.
  • Tergitol-7 in the medium inhibits Gram positive bacteria and Gram negative bacteria with the exception of coliforms.

Benefits of product

  • Ready-to-use agar medium
  • Functional tests according to ISO 1113
  • Reliable

Application benefits

  • Reference medium
  • Universal application
  • Differentiation of different bacteria

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