Topic summary
Blood group
Extracted from the Wikipedia article Blood type.
ABO blood group system
The ABO blood group system involves two antigens and two antibodies found in human blood. The two antigens are antigen A and antigen B. The two antibodies are A and B. The antigens are present on the red blood cells, and the antibodies in the serum. Regarding the antigen property of the blood, all human beings can be classified into four groups: those with antigen A (group A), those with antigen B (group B), those with both antigen A and B (group AB), and those with neither antigen (group O). The antibodies present together with the antigens are found as follows: