BLOOD GROUP O

Neither type A or B antigens are present on the surface of red blood cells in people who have group O blood. However, both anti-A and anti-B antibodies are present in the blood:

group O copy.png

Because of this, people with blood group O can only receive group O blood. They cannot receive group A, B or AB blood, as the anti-A and anti-B antibodies in their blood will attach to the type A and B antigens and destroy the blood cells, causing an immune response that can ultimately be fatal.

  • If someone with blood group O receives group A blood, the anti-A antibodies in their blood will attach to the type A antigens and destroy the blood cells.

  • If someone with blood group O receives group B blood, the anti-B antibodies in their blood will attach to the type B antigens and destroy the blood cells.

  • If someone with blood group O receives group AB blood, the anti-A antibodies in their blood will attach to the type A antigens, and the anti-B antibodies in the recipients’ blood will attach to the type B antigens and destroy the blood cells.

However, group O blood is compatible with all of the different blood types. This is why group O blood is known as the 'universal donor'.