Blood Transfusion.

Any blood transfusion is ideally safe if it does not cause agglutination in the recipient. Matching . Agglutination leads to serious results because clumped cells cannot pass through fine capillaries. The blood samples of the donor and the recipient are cross matched for compatibility before giving transfusion.

Mismatching Result.

If incompatible blood is transfused, dangerous hemolytic reaction occurs. Either the antibodies of the recipient destroy the RBC of donor or the antibodies of the donor hemolyze the RBC of the recipient Blood A.

Blood group A can be transfused only into A and AB recipients because they do not have anti – A antibodies.

Blood B.

Blood group B can be transfused only into B and AB recipients as they do not have anti – B antibodies.

Blood AB.

AB blood can be transfused only into AB recipients because they have neither anti – A, nor anti B antibodies.

Universal recipient.

AB blood group individuals are called universal recipients because they can receive transfusions of blood from any of the four blood groups.

Blood O.

It has neither A nor B antigen, but it does have anti – A and anti-B antibodies. An O recipient can only be given transfusion from a donor O.

Universal donor.

Phenotype O can also be used as donor for small transfusions to A, B and AB recipients because donor‘s antibodies are quickly absorbed by other tissues or greatly diluted in the recipient‘s blood stream.

O blood group individuals are called universal donors.

Secretors.

A and B antigens can also be present in saliva and other body fluids of some persons called secretors. Secretors have dominant secretor gene ―Se‖ on chromosome 19.

Parental Determinations.

Genetic analysis on the basis of blood groups helps in solving cases of disputed parentage. It can only be used to prove that an individual is not the parent of a particular child, Example1. A child of AB phenotype (IA I B) cannot be the child of a parent of phenotype O.

Example2.

Similarly a man of B phenotype cannot be father of a blood type A child, whose mother is of phenotype O. His father could either be A or AB phenotype.