The ABO blood group system is determined by the presence or absence of two antigens (A and B) on the surface of red blood cells. Type O individuals have neither antigen, while type AB has both.
What are the four main blood types?
How do I know if I have type A blood?
What does it mean to be Rh positive or negative?
Can someone with type O donate blood to anyone?
What are the possible combinations of ABO groups?
How do I determine my blood type if I don’t know it?
What is the significance of the Rh factor in blood types?
Results are for informational purposes only and do not constitute professional advice.
