Brilliance E. coli / Coliform Selective Agar 90mm Pk 10

Detect and enumerate Escherichia coli and other coliforms in food and water samples with selective, chromogenic Thermo Scientific™ Brilliance™ E. coli / Coliform Selective Agar.

The agar base uses two chromogens to differentiate between Escherichia coli and other coliforms. This results in purple E. coli, as they are able to cleave both chromogens with other coliforms, giving pink colonies.

The recovery and enumeration of Escherichia coli and coliforms are important indicators of environmental and food hygiene. Brilliance E. coli / Coliform Selective Agar contains two chromogenic agents:

• Rose-Gal: detects ß-galactosidase activity
• X-Glu: detects ß-glucuronidase activity

Detection of ß-glucuronidase activity is widely used to differentiate Escherichia coli, as this is present in E. coli but not in other members of the coliform group.

As most coliforms are lactose-positive, ß -galactosidase activity, encoded by the lacZ gene, is then used to differentiate this group from other organisms able to grow on the selective medium.

This results in purple E. coli, as they are able to cleave both chromogens with other coliforms, giving pink colonies, as they cleave only the galactoside chromogen.

The medium also contains sodium lauryl sulphate which acts as a selective agent, inhibiting the growth of Gram-positive organisms.

Due to the addition of tryptophan, the rapid confirmation of E. coli by the formation of indole using a spot indole test is possible.