What is ABO blood grouping system?
According to the ABO blood typing system there are four different kinds of blood types: A, B, AB or O (null). If you belong to the blood group A, you have A antigens on the surface of your red blood cells and B antibodies in your blood plasma. If you belong to the blood group B, you have B antigens on the surface of your red blood cells and A antibodies in your blood plasma. If you belong to the blood group AB, you have both A and B antigens on the surface of your red blood cells and no A or B antibodies at all in your blood plasma. If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma.