Wheat germ agglutinin (WGA) is a group of closely related isolectins that bind N-acetylglucosamine (preferentially dimers and trimers) and oligosaccharides containing terminal N-acetylglucosamine or chitobiose, structures common to many serum and membrane glycoproteins. WGA can also bind bacterial cell wall peptidoglycans, chitin, cartilage glycosaminoglycans, and glycolipids, and can be used for the purification of insulin receptors and neuronal tracing. WGA also interacts with some glycoproteins via sialic acid residues (see succinylated WGA). This WGA is conjugated to horseradish peroxidase (HRP) and can be used for both anterograde and retrograde neuronal transport studies. Supplied in a 2 mg package at 40 mg/ml ready for injection, the recommended inhibiting/eluting sugar is chitin hydrolysate or 500 mM N-acetylglucosamine.