2234 Listeria Fraser Broth Supplemented ISO, Condalab

Fraser Broth is the secondary enrichment step in the ISO 11290 protocol, following initial enrichment in Half-Fraser Broth. This formulation provides a rich nutrient base of Peptones, Beef Extract, and Yeast Extract to support the vigorous growth of Listeria. Selectivity is achieved through Lithium Chloride, Nalidixic Acid, and Acriflavine Hydrochloride, which work synergistically to suppress the growth of competitive flora such as Enterococci, Staphylococci, and Gram-negative bacteria. The medium is also differential: Listeria species hydrolyze Esculin to esculetin, which reacts with the Ferric Ammonium Citrate already present in this formulation to produce a blackening of the broth, providing a clear visual presumptive positive result.

Advantages

• All-in-One Formulation: Unlike the standard base (Cat. 1182), this version already contains the selective supplements and ferric citrate, reducing preparation time and potential for contamination.
• ISO 11290 Compliance: Fully meets the performance and compositional requirements for the secondary enrichment phase of Listeria detection.
• Clear Visual Indicator: The rapid blackening of the broth allows for easy presumptive identification of Listeria presence.
• High Specificity: The optimized concentration of antibiotics ensures the suppression of background microflora that could lead to false positives.
• Excellent Recovery: Provides the high-density growth required for subsequent successful isolation on selective agar plates (such as Oxford or Palcam).

Technical specifications

Available packaging options