1274 XLD Agar (Xylose Lysine Desoxycholate Agar) ISO, Condalab

XLD Agar ISO is designed to allow the growth of Salmonella while providing clear visual differentiation from other enteric bacteria. The medium utilizes Xylose as a primary fermentable sugar; because most enteric bacteria (except Shigella) ferment xylose, they produce acid and turn the medium yellow. However, Salmonella species subsequently decarboxylate the L-Lysine, which increases the pH and reverts the colony and surrounding medium to a red color. The selectivity is achieved through Sodium Deoxycholate, which inhibits the growth of Gram-positive flora. To further differentiate Salmonella, Sodium Thiosulfate and Ferric Ammonium Citrate are included to detect the production of hydrogen sulfide (H₂S), resulting in colonies with characteristic black centers. Phenol Red serves as the pH indicator for the fermentation and decarboxylation reactions.

Advantages

• ISO 6579 Compliance: Formulated specifically to meet international standards for the horizontal method of Salmonella detection.
• High Diagnostic Accuracy: The combination of xylose fermentation, lysine decarboxylation, and H₂S production provides a high level of presumptive identification.
• Balanced Selectivity: Effectively inhibits Gram-positive bacteria and suppresses many non-target Enterobacteriaceae without being overly toxic to Salmonella.
• Clear Visual Contrast: Red colonies with black centers are easily distinguished from yellow, acid-producing coliforms.
• Industry Standard: Widely used in food quality control, veterinary diagnostics, and environmental monitoring for pathogenic enteric bacteria.

Technical specifications

Available packaging options