There are mainly 4 main blood groups:
- A blood group – A blood group persons has A antigens on RBC surface and anti- B antibodies in plasma
- B blood group- B blood group persons has B antigen on RBC surface and anti- A antibodies in plasma
- AB blood group – AB blood group persons have both A and B antigen in RBC and no antibodies in plasma
- O blood group – O blood group individual have anti A and anti B antibodies in plasma.