Several major Type O blood shortages, including crises at the National Institutes of Health highlight the importance of creating a versatile blood type. In the rare instance that someone receives a transfusion of the wrong type, deadly reactions (caused by sugar molecules on the surfaces of red blood cells) can cause the immune system to go haywire.
Henrik Clausen, a professor at the University of Copenhagen in Denmark, published research in Nature describing a way to convert any kind of blood into Type O — the type that almost anyone can tolerate. He discovered enzymes that shear the problem-causing sugars from the surfaces of A, B and AB type red blood cells. Produced by bacteria, the molecular machines could theoretically turn any kind of blood into Type O.