HEMAGGLUTINATING ACTIVITY IN EXTRACTS OF SOME MARINE MEXICAN ALGAE

Eleven algal species collected along the coast of the states of Guerre ro and Oaxaca, Mexico, were analyzed to detect agglutinating activity in human blood erythrocytes in A(+), B+ and O+ groups. Aqueous extract s were prepared and frozen until analysis. Microtitration tests were p erformed with serial dilutions of algal extract and with a constant vo lume of human erythrocytes at 2 %. They were left to settle, and after two hours, observed under a microscope. Out of 15 samples analyzed, 2 0 % showed positive agglutination. The active species were Codium gira ffa, Hypnea spinella and Ulva lactuca. This is the first report of agg lutinating activity from Mexican algae, and for Codium giraffa and Hyp nea spinella.