EZ-CHROM Listeria

EZ-CHROM* Listeria is a chromogenic media for the isolation, detection and differentiation of Listeria monocytogenes from other bacteria in food. Product can be ordered as 20 prepared plates or a 250 gram bottle of powdered media.

Listeria monocytogenes is a pathogenic bacterium which can cause serious food poisoning. Since L. monocytogenes and L. innocua have similar biochemical properties, they cannot be differentiated on traditional media (PALCAM, Oxford).

On EZ-CHROM Listeria, L. monocytogenes colonies have a specific blue color surrounded by a white opaque halo. The Colorex Listeria method allows detection of negative samples in only 2 days. This method requires only a single half Fraser broth enrichment step.

Confirmation of positive samples can be performed by picking a suspect colony directly from the Colorex™ Listeria plate and transferring it to Colorex™ Identification Listeria giving a next day confirmation that the isolate is indeed L. monocytogenes.


EZ-CHROM Listeria is 100% sensitive for L. monocytogenes which will appear as blue colonies with a diameter less than 3mm, regular and white halo. Other bacteria will appear as blue colonies without a halo, colorless, other color, or inhibited.

*EZ-CHROM plates are a Colorex™ product, EZ-CHROM powder is a CHROMagar™ product