from web md http://www.webmd.com/news/20070403/converting-blood-types-may-be-possible Converting Blood Types May Be Possible Technique Makes Type A, B, or AB Blood Act Like Type O Blood By Miranda Hitti WebMD Health News Reviewed by Louise Chang, MD April 3, 2007 -- Scientists have found a way to convert blood types in a test tube. If their approach works in people, it could be a boon to the blood supply. The news appears in Nature Biotechnology. The four blood types are A, B, AB, and O. They are based on the presence or absence of specific antigens -- foreign substances that cause the production of antibodies. Blood type is inherited. To avoid potentially deadly reactions, type A blood can only be given to people with type A or type AB blood. Type B blood can only be given to people with type B or AB blood. Type O blood is often in demand because it can be safely used in any patient. Scientists have long looked for ways to make type A, type B, or type AB blood compatible with anyone. But until now, those attempts have had limited success. Now, scientists report success with a new technique tested in a lab. The researchers studied 2,500 enzymes made by fungi or bacteria and found two families of enzymes that make type A, type B, or type AB blood act like type O blood. Scientists working on the study included Qiyong Liu of ZymeQuest, the Massachusetts-based company developing the enzyme technique. Their technique needs further testing. But if it succeeds, it "would substantially reduce pressure on the blood supply," states a Nature Biotechnology editorial. The editorialists included Geoff Daniels, PhD, FCRPath, of the Bristol Institute for Transfusion Sciences in Bristol, England.