Blood types, for over a century, have been an important classification that have saved many lives; they have also posed major limitations in blood storage, but that may now be history. A scientific breakthrough that can convert Types A, B, and AB blood into Type O -- the universal donor blood group that can be given to anyone -- could help alleviate blood shortages and reduce the danger of accidental blood-type mismatches. An international team of scientists announced the research discovery, which involves isolating two bacterial enzymes that break down and remove the sugar molecules (antigens) on the surface of A, AB and B red blood cells that can cause potentially deadly immune reactions in patients transfused with mismatched blood. If proven safe and cost-effective in clinical trials, the process will have a significant impact.