Question

Blood agglutination tests are used in
(a)Antigen-antibody reaction
(b)Animal relations
(c)Immunity
(d)None of the above

Answer 1

Hint: Agglutination reactions are used to test the presence of antibodies in blood by mixing it with particular antigens. The agglutination indicates that the blood has reacted with a certain type of antibody hence making it not compatible for transfusion of the blood containing that type of antibody.

Complete answer:
-In humans, there is ABO blood grouping system. Presence or absence of antigen A and B determine the blood group as A, B, AB and O.
-Antibodies (agglutinins) for the antigens A and B exist in the plasma and are termed as anti- A and anti- B.
-The corresponding antigen and antibody are never found in the same blood as when they are mixed together, they form antigen-antibody complexes and agglutinate the blood.
-For testing the ABO group, we need to take two slides, a blood sample, anti A serum, anti B serum, and dropper.
-Now take a clean slide and label it as anti-A and using a dropper drop add two drops of anti A serum. Do the same with the second slide and label it as anti B.
-Now add a drop of a blood sample to both the slides.
-Check on which slide agglutination took place.
-Based on the agglutination following results can be drawn- if anti-A get slides to get agglutinated then the blood group is A. Similarly, for anti B slide it will be blood group B.
-If the blood on both the slides gets agglutinated then the blood group is AB and if not then it is blood group O.
-The blood agglutination test is done to detect the blood group and is used in antibody and antigen reactions.
So, the answer is ‘antigen-antibody reactions'.

Note: when blood transfusion is done, it is important to remember that the donor’s blood must not contain red blood cells that the recipient’s antibody can agglutinate. That is why it is seen that group O are universal donors and group AB is the universal recipient.