XLD Agar (Xylose-Lysine-Deoxycholate) – Selective solid media for microbiology

XLD Agar (Xylose Lysine Deoxycholate Agar) is a moderately selective differential medium used for the isolation and differentiation of enteric gram-negative pathogens, particularly salmonella and shigella in clinical, environmental and food samples.

It is based on the fermentation of xylose, lactose and sucrose, the decarboxylation of lysine and the production of hydrogen sulfide for the primary differentiation of shigella and salmonella.

XLD agar, , is one of the media recommended in the American Pharmacopoeia (USP) and European (EP) for the enumeration of microorganisms.