Blood Transfusion and Agglutination

Consider a patient with blood type A with antigen-A on their red blood cells. Naturally, this patient’s blood has no antibodies against antigen A.

If this patient is injected with blood of type B, their immune system will detect the antigen-B in the incoming blood as foreign, and produce antibodies against it, leading to the rejection of the blood transfusion.

Using this antigen-antibody reaction, the agglutination test can detect a patient’s blood type.

A few drops of type A blood, when mixed with serum-containing antibody A, will form visible clumps by a process called agglutination. Similarly, type B blood forms clumps with antibody-B.

Type AB blood contains both antigens, therefore, it agglutinates with both antibodies A and B.

Since type-O blood has no antigens on the surface of red blood cells, it does not react with antibody-A or antibody-B. Therefore, clumps do not form.

Similarly, the Rh blood group is detected using D-antibodies. Positive clump formation indicates Rh-positive blood, and a negative result infers Rh-negative.

During a blood transfusion, the donor and recipient’s blood must be compatible to avoid immune cross-reactivity.

Type A blood cannot be given to an ac