Affinity purified Tulip sp. Lectin (TL) lectin is a tetrameric protein composed of four identical subunits which are not held together by disulfide bonds. TL is not blood group specific, but it does agglutinate type O erythrocytes more readily than either A or B cells. It has a carbohydrate specificity of N-acetylgalactosamine, galactose and fucose, and elutes with fetuin or thyroglobulin.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 Tulip sp. Lectin (TL). Colloidal gold labeled lectins can be viewed via electron microscopy.