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.