A blood type is a classification of blood based on the presence or absence of certain antigens and antibodies.
Antigens:
Antigens are substances on the surface of red blood cells that can induce an immune response in the recipient’s body.
Antibodies:
Antibodies are proteins in the plasma that recognize and attack foreign substances (antigens) and aid in eliminating them from the body.
ABO Blood Types:
The ABO blood typing system categorizes blood into four main groups: A, B, AB, and O.
Type A:
Red blood cells have A antigens on their surface, and antibodies against B antigens in the plasma.
Type B:
Red blood cells have B antigens on their surface, and antibodies against A antigens in the plasma.
Type AB:
Red blood cells have both A and B antigens on their surface, but no antibodies against A or B antigens in the plasma.
Type O:
Red blood cells have neither A nor B antigens on their surface, but antibodies against both A and B antigens in the plasma.
Rh Factor:
In addition to the ABO system, blood types are also classified based on the presence or absence of the Rh antigen.
Rh Positive:
If red blood cells have the Rh antigen on their surface, the blood type is classified as Rh positive (Rh+).
Rh Negative:
If red blood cells do not have the Rh antigen on their surface, the blood type is classified as Rh negative (Rh-).