Thermo Scientific has launched a new chromogenic culture medium to enhance the detection and enumeration of E. coli and coliforms - important indicators of environmental and food hygiene. Thermo Scientific Selective E. coli/coliform Chromogenic Medium provides a rapid and easily visualised result within 24 hours, reducing the need for further lengthy confirmation steps.

Thermo Scientific Selective E. coli/coliform Chromogenic Medium can be used without the need for pre-enrichment or the use of a filter membrane. The selective agent in the medium, sodium lauryl sulphate, inhibits the growth of Gram-positive microorganisms that may interfere with the growth of the target organisms. Two chromogens then allow E. coli and coliform colonies to stand out from any other organisms that may grow on the selective medium, allowing accurate colony counts to be obtained of each.

Chromogen X-Gal detects the presence of b-galactosidase activity in coliforms (including E. coli), causing them to be bright pink in colour. In addition X-Glu detects the enzyme b-glucuronidase, which is possessed by E. coli but not by other coliforms. The resulting blue chromophore causes E. coli colonies to appear purple, allowing them to be easily differentiated from other coliforms.

To find out more about Thermo Scientific Selective E. coli/coliform Chromogenic Medium and other products in the Thermo Scientific range for hygiene monitoring and testing:

Telephone: +44 (0) 1256 841144
Fax: +44 (0) 1256 329728
Email: leslie.bissell@thermofisher.com
or visit the Thermo Scientific website at http://www.oxoid.com/