Why does blood type O have no antigens?

AB type are the opposite both antigens on red fells but no A or B antibodies which is why they are the universal receiver. All this is assuming no other circulating antibodies which can be acquired either through previous transfusion or pregnancy. read more

Since O-type red blood cells contain no antigens , and the plasma with the antibodies are not transfused, it can be donated to everyone, barred that the rhesus factor matches. read more

There is more to blood types than most people think, actually including most doctors. For example, in the ABO system, having type O blood does not mean you lack ABO antigens. read more