Ulex europaeus agglutinin (UEA I+II) is affinity purified consists of two hemagglutinins (UEA I and UEA II). The two lectins can be separated by salt or ethanol precipitation. Both have been sequenced and are homologous with each other, as well as homologous with other legume lectins of various specificities. Carbohydrate-binding peptides have been isolated for each lectin after peptidase digestion, and these peptides also exhibit homology with other such peptides. UEA I interacts specifically with blood group H type 2 antigen, which is expressed in individuals with type O blood and to a lesser degree in individuals with type A or B blood. UEA II is not blood group specific but the best inhibitors are the H type oligosaccharides.Biotin is a small molecule involved in a wide range of metabolic processes. This ligand forms a complex with Avidin and Streptavidin, resulting in the strongest non-covalent protein-ligand interaction known. Biotinylated Ulex europaeus Lectin (UEA I+II) has an appropriate amount of biotin bound to provide optimum detection characteristics when using an Avidin-HRP or Streptavidin-HRP conjugate. Biotinylated lectins allow for more sensitive detection in ELISA and Western-blotting applications.