Human blood group and classification of ABO system

By Ankita Rai | Last Updated: November 18, 2018 Previous       Next

Transfer of blood from one person to another person or donor to acceptor, the donor blood must be matched with the acceptor blood group. If it is not matched, it causes the death.

In RBC membrane, several class of antigen is present in two most types:

1. ABO system
2. Rh factor

ABO System

In ABO system cell membrane of RBC contain antigen called Agglutinogen. There is two type of Agglutinogen present in human blood A and B and these are divided into four groups.

• Blood group A
• Blood group B
• Blood group AB
• Blood group O

Blood group A– Person whose RBC membrane contains A Agglutinogen.

Blood group B– Person whose RBC membrane contains B Agglutinogen.

Blood group AB– Person whose RBC membrane contains A and B both Agglutinogen.

Blood group O– Person whose RBC membrane contains no Agglutinogen.

Antibodies (Agglutinins) of ABO Group

Antibodies present in plasma. It divided into two subclasses.

1. Anti A
2. Anti B

Blood group A– plasma contain Anti B antibody.

Blood group B– plasma contain Anti A antibody.

Blood group AB– plasma contains no antibody.

Blood group O– plasma contains A and B both antibody.

Mismatching in Blood Group

• Donor having blood group A contains A Agglutinogen (antigen) in RBC and Anti B agglutinin (anti B antibodies) in plasma.
• Acceptor having blood group B contains b Agglutinogen (antigen) in RBC and Anti A antibody in plasma.
• After mixing donor RBC clump and used by anti A antibody present in plasma of acceptor.

e.g.- Group A blood transferred in a person belonging to blood group B.

Table display that which blood group can be transferred to which blood group.

Note: AB is acceptor, it can accept from all group and O is all donor, it can donate to all group.