Thermo Scientific™

Chromogenic Listeria Agar (ISO) (Dehydrated)

Isolate, enumerate and differentiate Listeria species and Listeria monocytogenes from food samples with Thermo Scientific™ Oxoid™ Chromogenic Listeria Agar (ISO) (Dehydrated). Chromogenic Listeria Agar (ISO) contains lithium chloride, polymyxin B, nalidixic acid, and amphotericin which act to inhibit non-target organisms. A combination of chromogenic and phospholipase enzyme reactions easily differentiate Listeria monocytogenes (blue colonies surrounded by an opaque halo) from other Listeria spp. (blue colonies without an opaque halo). 
Back to top
Listeria monocytogenes is the most common pathogenic Listeria spp. and has been shown to be pathogenic to both humans and animals. Chromogenic Listeria Agar (ISO) is designed to identify Listeria spp. based on their utilization of a chomogenic substrate.
  • Easy-to-read: chromogenic and phospholipase enzyme reactions easily differentiate Listeria monocytogenes from other Listeria spp.
  • Adheres to ISO 11290-1:1997 standards.
  • Superior to PALCAM and Oxford medium for the isolation of Listeria monocytogenes1.
The presence of the chromogenic substrate for the detection of ß-glucosidase (an enzyme common to all Listeria spp. and to a few strains of Enterococci and Bacilli) results in chromogenic activity.
Further differentiation of Listeria monocytogenes and other Listeria spp. is facilitated by the addition of phosphatidylinositol or lethicin substrate for the detection of phospholipase enzyme.

Not all products are available for sale in all territories. Please inquire.
Remel™ and Oxoid™ products are now part of the Thermo Scientific™ brand.
1. Gently agitate the bag; then using a microbiological loop, inoculate onto Chromogenic Listeria Agar (according to Ottaviani and Agosti) and a second selective medium (e.g. PALCAM Agar - CM0877 & SR0150). Incubate at 37°C for 24h ± 3h, and if necessary, for an additional 24h ± 3h (PALCAM Agar should be incubated under micro-aerobic conditions for best results).