ABO grouping: Father of blood Grouping Karl landsteiner
ABO grouping is based on the presence or absence of two surface antigens (chemicals that can induce immune response) on the RBCs namely A and B.
Plasma of different individuals contains natural antibodies (proteins produced in response to antigens).
Blood of a donor has to be carefully matched with the blood of a recipient before any blood transfusion to avoid severe problems of clumping (destruction of RBC).
