1080 XLD Agar (Xylose Lysine Deoxycholate Agar) EP/USP, Condalab

XLD Agar was originally developed to increase the recovery of Shigella, which is often inhibited by more aggressive selective agents. The medium contains three fermentable carbohydrates: Xylose, Lactose, and Sucrose. L-Lysine is included to allow for the differentiation of Salmonella; once xylose is exhausted, Salmonella decarboxylates the lysine, causing a reversion to an alkaline pH. Sodium Deoxycholate acts as a selective agent that inhibits Gram-positive bacteria. Phenol Red serves as the pH indicator, turning yellow under acidic conditions and red/pink under alkaline conditions. To detect hydrogen sulfide (H₂S) production, Sodium Thiosulfate and Ferric Ammonium Citrate are included; H₂S-producing organisms like Salmonella develop characteristic black centers.

Advantages

• EP/USP/ISO Compliance: Formulated to meet the global regulatory standards for the detection of Salmonella in pharmaceutical and food samples.
• High Sensitivity for Shigella: Provides better recovery of Shigella species compared to other selective enteric media like SS Agar or Hektoen.
• Triple Differentiation: Differentiates based on xylose fermentation, lysine decarboxylation, and H₂S production.
• Clear Visual Identification: The color contrast between colonies (Red vs. Yellow) and the presence of black centers allows for rapid presumptive identification.
• Inhibition of Contaminants: Effectively suppresses Gram-positive flora and many non-pathogenic Gram-negative bacteria.

Technical specifications

Available packaging options