HEMAGGLUTINATION-INHIBITION TEST (HI)

Purpose: To quantitate serum antibody to a specific avian (antigen)

1.  Avian viruses which can agglutinate avian RBCs (hemagglutination) include NDV, Influenza, and ADENO 127. In addition to viruses, Mycoplasmas are also capable of hemagglutinating avian RBCs.

2. Antibodies directed against these organisms will inhibit hemagglutination.

3.  Procedure:

a. A constant amount of hemagglutinating (HA) antigen is added to each well in a microtiter plate.

b. The test serum is then placed in the first well and serially diluted.

c.  The plates are incubated for one hour and then chicken RBCs are added to each well. If antibody is present in the test serum the RBCs will not agglutinate with the HA antigen.

d.  HI NEGATIVE wells will have a diffuse sheet of agglutinated RBCs covering       the bottom.

e.  HI POSITIVE wells will have a well circumscribed button of unagglutinated       RBCs

 

HI NEGATIVE AGGLUTINATION PICTURE HI POSITIVE NO AGGLUTINATION

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