XYLOSE LYSINE DEOXYCHOLATE AGAR (XLD AGAR) PLATE

XLD (Xylose Lysine Deoxycholate Agar) Agar Plate is a selective and differential culture medium used for the isolation and differentiation of Salmonella and Shigella species from clinical specimens, food products, water and dairy samples. It is widely used in microbiology laboratories for the detection of enteric pathogens. It is also recommended for microbiological testing of food and water quality.
Sodium deoxycholate in the medium inhibits the growth of Gram-positive organisms thereby permitting the selective recovery of enteric bacteria. Xylose is the primary fermentable carbohydrate used for differentiation based on the pattern of fermentation. Most enteric bacteria ferment xylose and form yellow colonies, but Shigella is non-fermentative and produces red colonies. Lysine decarboxylation can be used to identify Salmonella as it brings the pH back up to alkaline due to the presence of lysine. In addition, sodium thiosulphate and ferric ammonium citrate are used to detect hydrogen sulphide production leading to characteristic black centred colonies of H₂S-producing Salmonella.
XLD Agar Plate is recommended for the selective isolation and enumeration of Salmonella typhi and other Salmonella species. It is widely used as per USP and European Pharmacopoeia (EP) microbial limit testing standards.

XLD Agar is a selective and differential culture medium for isolating and differentiating Salmonella and Shigella from clinical, food, water, and dairy samples.