Affinity purified Wisteria floribunda agglutinin or lectin (WFA/WFL) is composed of four subunits. This lectin is not blood group specific although it does react stronger with human type A1 cells over A2, B, or O cells. The presence of a sialic acid residue may cause a lack of WFA reactivity. WFA contains a strong hemagglutinin activity and is a potent mitogen, both strongly inhibited by GalNAc, although mitogenic activity is also inhibited by N,Nâ€™-diacetylchitobiose.Colloidal gold can be used to visualize localization of specific saccharide moieties and examine the distribution of plasma membrane glycoproteins based on the binding pattern of Wisteria floribunda Lectin (WFA/WFL). Colloidal gold labeled lectins can be viewed via electron microscopy.