Blood Types and Rh Factor

Whether or not a recipient can accept a donor's blood depends on his or her blood type.
Blood types – the most famous being A, B and O – are descriptions of certain antigens found on red cells. Type A blood has A antigens on the red blood cells and lacks B antigens. Type B blood has B antigens and lacks A antigens Type AB blood has both antigens. Type O blood lacks both A abd B antigens, but has others. When talking about blood types, we must also consider the Rh factor.

Rh Factor
The Rh factor is an inherited blood group on red blood cells like the ABO blood types. The 86 percent of Americans who have it are "Rh-positive," and those who don't are "Rh negative." Your blood type and Rh factor determine:
Which types of blood you can receive Which blood type recipients can use blood that you donate.