Erythrina cristagalli lectin or agglutinin (ECL/ECA) is affinity purified lectin consists of two subunits with molecular weights of 28,000 and 26,000. ECL binds to carbohydrate structure in membrane and serum glycoproteins of mammalian cells. The shape of the lectin binding domains may resemble cavity type with GalÎ²1->4GlcNAc as the core binding site with additional one to four sugar subsites and is most complementary to a linear trisaccharide. Some GalÎ²1-related oligosaccharides are the major structures for lectin binding. Lectin binding activity can be abolition through salic acid substitution. This allows for specificity to fractionate and isolate mammalian glycoproteins. 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 Erythrina cristagalli (Coral tree) Lectin (ECL/ECA). Colloidal gold labeled lectins can be viewed via electron microscopy.