Product overview

Harlequin® Listeria Chromogenic Agar (LCA) is a selective and differential medium used for the isolation and presumptive identification of Listeria monocytogenes from food and related samples, in line with ISO 11290-1:2017. The formulation incorporates selective agents (lithium chloride and antimicrobial supplements) to inhibit competing flora, while chromogenic substrates enable detection of β-glucosidase activity common to Listeria species. A proprietary lecithin substrate further differentiates L. monocytogenes through phospholipase activity, producing distinctive blue colonies surrounded by an opaque halo. This dual-reaction system allows clear differentiation between L. monocytogenes and other Listeria spp. LCA Agar is part of Neogen’s One Broth One Plate Listeria (OBOP-L) workflow, validated to ISO 16140-2 and certified by AFNOR.