•A hemolytic reaction occurs with a Rh or ABO incompatiblity
•The Rhesus factor is the presence of proteins on the cell, which is what the bosy reacts to. Rh negative blood can donate to Rh positive blood if it's the same type, because there are no proteins.
•O-negative is the universal donor, because it does not have A or B properties, and A and B blood types do not have O antibodies.
•AB patients can receive both A & B blood types, as long as there is a Rh compatibility.