Although more than 400 blood groups have been identified,the ABO blood group system remians the mostimpoant in clinical medicne because :
It was the first blood group system to be discovered
It has four different blood groups A,B, AB, O (H).
ABO(H) antigens are present in most body tissues and fluids.
ABO(H) antibodies are invariably present in plasma when persons RBC lacks the corresponding antigen
. ABO(H) antibodies are invariably present in plasma when persons RBC lacks the corresponding antigen