Introduction
=> Based on the presence and absence of antibodies, the blood is classified into different groups.
=> Further, while classification, the presence and absence of the inherited antigenic substances also considered.
=> The types of blood groups are inherited and represent contributions from both the father and the mother.
ABO Blood Group System
=> In human blood, usually, there are two antigens and antibodies.
=> The two antigens are antigen A and antigen B.
=> The two antibodies are antibody A and antibody B.
=> The antigens are remaining in the red blood cells, whereas the antibodies are found in the serum.
=> Based on the antigen property, the blood group of all human beings can be classified as −
* Blood Group A − antigen A and antibody B
* Blood Group B − antigen B and antibody A
* Blood Group AB − antigen A and antigen B and no antibody
* Blood Group O − no antigen, but antigen A as well as antibody B
=> Consideration of the ABO system is the most imperative while transfusion of human blood.
=> The ABO blood group systems were first discovered by Karl Landsteiner in 1901.
Rh Blood Group System
=> The Rh system (the meaning of Rh is Rhesus) is another significant blood-group system. It is very important to match Rh system while blood transfusion.
=> Rh antigen first studied in Rhesus monkeys; therefore, its name is given Rh factor/system.
=> The person who does not have Rh antigen is known as Rh negative (Rh-ve) and the person who has the Rh antigen is known as Rh positive (Rh+ve).