Xylose Lysine Deoxycholate (XLD) Agar, USP is a selective and differential medium designed for the isolation and identification of Gram-negative enteric pathogens, particularly Salmonella and Shigella species, from clinical, environmental, food, and pharmaceutical samples.

Formulated in accordance with United States Pharmacopeia (USP) guidelines, XLD Agar supports growth promotion testing and serves as a validated medium for the microbiological examination of nonsterile products. The medium utilizes xylose fermentation, lysine decarboxylation, and hydrogen sulfide (H₂S) production as key differentiation mechanisms, enabling precise identification of target organisms.

Typical colony characteristics include:

Salmonella spp. — red colonies with black centers (H₂S positive)

Shigella spp. — red colonies (non-H₂S producers)

Coliforms — yellow colonies from carbohydrate fermentation

Each plate is manufactured using optically clear, heavy-duty polystyrene for superior visualization and durability. Raised stacking rings prevent slippage during storage, while breathable packaging minimizes condensation and preserves media integrity.

Features and Benefits:
• USP-compliant formulation for pharmaceutical and food testing
• Selective and differential for Salmonella and Shigella spp.
• Distinguishes lactose and xylose fermenters by colony color
• Reliable medium for enteric pathogen detection in diverse matrices
• Durable polystyrene plates ensure clarity and reduce breakage
• Breathable packaging maintains optimal humidity during storage