Differences between Blood groups 'AB' and 'O' on the basis of antigens:
| Blood group 'AB' | Blood group 'O' |
|---|---|
| The persons whose RBCs have both types of antigens, i.e. both A and B, belong to the 'AB' blood group. | The persons whose RBCs have no antigens, i.e., neither A nor B have the 'O' blood group. |