H blood group detection by the L-fucose binding lectin of the green marine alga Ulva lactuca.

Extracts of the green marine alga Ulva lactuca collected along the seashore of Tel-Aviv exhibit hemagglutinating activity towards papain-treated human erythrocytes. This hemagglutinating activity was shown to be inhibited by L-fucose and EDTA, and to be relatively resistant to heating at 60 degrees C, while sensitive to low pH. Like the lectin of Ulex europeus, the Ulva lectin exhibits blood group H specificity. It agglutinates most strongly erythrocytes of blood group 0(H) followed by B greater than A greater than AB. A2 and A2B erythrocytes are agglutinated by it considerably more strongly than A1 and A1B respectively. Bombay 0(hh) type erythrocytes are almost non-reactive. The lectin can be stored at -20 degrees C for years.