Lens Culinaris Agglutinin (LCA), Biotinylated, 5 mg, recognizes sequences containing alpha-linked mannose residues but recognizes additional sugars as part of the receptor structure, giving it a narrower specificity than Con A. An alpha-linked fucose residue attached to the N-acetylchitobiose portion of the core oligosaccharide significantly enhances affinity. By exploiting this narrower specificity, glycoproteins and glycopeptides can be subfractionated with LCA after initial isolation with Con A. Biotinylated Lens culinaris agglutinin has an appropriate number of biotins bound to provide the optimum staining characteristics for this lectin. This conjugate is supplied essentially free of unconjugated biotins and is preserved with sodium azide.