What is agar gel immunodiffusion test?

The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the nucleoprotein (NP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes.

What happens during an immunodiffusion test?

Immunodiffusion is a diagnostic test which involves diffusion through a substance such as agar which is generally soft gel agar (2%) or agarose (2%), used for the detection of antibodies or antigen.

What is the main principle of Immunodiffusion?

PRINCIPLE: Immunodiffusion in gels encompasses a variety of techniques, which are useful for the analysis of antigens and antibodies. An antigen reacts with a specific antibody to form an antigen-antibody complex, the composition of which depends on the nature, concentration and proportion of the initial reactants.

How does agar gel immunodiffusion ( AGID ) Test work?

The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the ribonucleoprotein (RNP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes.

How does the agar gel precipitation test work?

AGAR GEL PRECIPITATION TEST (AGPT) OR OUCHTERLONY’S TEST. Principle. Antigen and antibody placed in wells cut in agar gels diffuse and form an opaque band of precipitate of the antigen-antibody complex in the zone of optimal proportions. Since each antigen combines with its own specific antibody, an antigenic mixture will give multiple bands.

Which is the basis for the immunodiffusion test?

The basis for the immunodiffusion test is concurrent migration of antigen and antibody towards each other through an agar or agarose gel. As the antigen and antibody come in contact, they combine to form a precipitate that is trapped in the gel matrix and produces a visible line.

How is an antibody used in radial immunodiffusion?

In the test, antibody is incorporated into agar and poured into a glass plate to form a uniform layer. Circular wells are cut into the agar and antigen is introduced into the wells.