SoylentNews

theronb writes:

According a summary in Chemical & Engineering News of a much more technical paper in the Journal of the American Chemical Society (referenced in the C&EN summary):

Hospitals keep stores of universal, type O blood for situations when a patient with an unknown blood type needs an emergency transfusion. The other types—A, B, and AB blood—can trigger a potentially fatal immune response in an unmatched recipient. Now, bioengineers have taken a step on the path toward making all blood universal—by broadening an enzyme’s ability to remove antigens on the surface of red blood cells (J. Am. Chem. Soc. 2015, DOI: 10.1021/ja5116088).
The quest for universal blood has tempted researchers since the discovery in the 1980s of coffee bean enzymes that could turn type B blood into O. The four main blood types each have distinctive sugar chains on the surface of their red blood cells.

Soylentils will note the intersting link to coffee.

Meanwhile, other scientists have claimed to have developed an enzyme that convert other blood types to that of the universal donor.

“We produced a mutant enzyme that is very efficient at cutting off the sugars in A and B blood, and is much more proficient at removing the subtypes of the A-antigen that the parent enzyme struggles with,” said David Kwan, the lead author of the study and a postdoctoral fellow in the Department of Chemistry. Their job, however, is not yet done. Whilst the enzyme was able to remove the vast majority of antigens from type A and B blood, they were not able to remove all of them. As the immune system is incredibly sensitive to blood groups—so much so that even small amounts of residual antigen can trigger an immune response—the scientists must first be certain that all antigens are absent.