Wheat germ agglutinin (WGA) binds N-acetylglucosamine, preferentially to dimers and trimers of this sugar. It can bind oligosaccharides containing terminal N-acetylglucosamine or chitobiose, structures common to many serum and membrane glycoproteins. Bacterial cell wall peptidoglycans, chitin, cartilage glycosaminoglycans, and glycolipids can also bind WGA. Native WGA also interacts with some glycoproteins via sialic acid residues (see succinylated WGA). This conjugate features a ratio of biotin to lectin protein that provides optimal avidin/streptavidin and lectin binding activity. Supplied essentially free of unconjugated biotins, it is preserved with sodium azide.