Canadian scientists could change blood type

Researchers at the University of British Columbia have discovered a way to turn Type A blood into the more in-demand Type O.
With the ability to switch types, hospitals could greatly expand the number of people they could donate a given unit of blood to.
There are four main blood types: A, B, AB and O.
Type A and B blood have specific antigens which mean it can only be donated to other people with those same antigens. Type AB blood has both antigens. So Type A blood can only be given to people with either Type A or Type AB blood, for example. If the wrong blood is given, the recipient’s immune system will attack the new blood cells.