Vicia ervilia agglutinin (VEA) is isolated from bitter vetch seeds. It has a molecular weight of 60 kDa and is composed of four subunits. It has an isoelectric point between pH 5.8 and pH 7.8. Sugar analysis of VEA has shown negligible amounts of carbohydrate (about 1 mol glucose per unit of MW). VEA agglutinates human erythrocytes of A, B, and O type. This lectin has possible utility as a biospecific adsorbent especially for virus purification, and material recovered from the biospecific adsorption step is homogenous at neutral pH.

The agglutination is inhibited by the presence of glucose, fructose, D-mannose, alpha-methylmannoside, N-acetyl glucosamine, sucrose, maltose, melezitose and trehalose; mannose and trehalose are the strongest inhibitors. No inhibition is caused by galactose, galactoseamine, N-acetyl galactoseamine, fucose, N-acetyl mannoseamine, cellobiose, lactose or sialic acid.