Matching blood types from donor to recipient is one of the major problems in organ donation. Now, a team of researchers in Canada has developed an enzyme treatment to convert donated organs to the universal O blood type, allowing them to be safely transplanted into any patient.

A person's blood type is determined by the antigens on the surface of their red blood cells. Those with type A blood have the A antigen, type B has the B antigen, AB has both and O has neither. For blood transfusions or organ transplants, these types need to be matched to prevent dangerous immune responses like organ rejection, but that's a messy process that sees many patients missing out.