Is there a Universal Donor Group?
In the past, type O Blood was given to virtually anyone except those that were termed 'rare' Blood. Donors of Blood group O were always referred to as 'universal donors'. Today, because of new research and a better understanding of the complex issues regarding immune reaction related to incompatible donor Blood cells, type O Blood is no longer seen suitable.
There is no "Universal Donor."
With further research, it was seen that even O- donors have some antibodies in their blood that can cause reactions in the recipients. Doctors/nurses now combine or cross-match a small sample of the donor's blood with that of the recipient's to check if they are compatible.
The terms universal donor and universal recipient are an over-simplification, because they only consider possible reactions of the recipient's anti-A and anti-B antibodies to transfused red blood cells, and also possible sensitization to RhD antigens (the Rhesus factor or Rhesus D antigens