Isolated from tomatoes, affinity-purified Lycopersicon esculentum lectin (LEL/LEA) has a carbohydrate specificity toward GlcNac. Composed of a single stable subunit, LEL is a useful marker of tracking vasculature in rodents and in neuroscience research. This lectin has an unusually high carbohydrate content of about 50 percent arabinose and galactose. LEL is non-specific agglutinates human erythrocytes A, B, O, or AB blood types. Protease-treated erythrocytes are slightly more sensitive to agglutination by this lectin.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 Lycopersicon esculentum Lectin (LEL/LEA). Colloidal gold labeled lectins can be viewed via electron microscopy.