VMC 221: Veterinary Immunology and Serology (1+1)

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. Setting up the reaction in adjacent wells assesses the immunological relationship between two antigens.

  • When the lines are confluent it indicates immunological identity in terms of antiserum used.
  • A spur develops with partially related antigens.
  • The lines cross indicate unrelated antigens.

Agargel immuno diffusion test

A). Pattern of identity, B). Pattern of partial identity, C).Pattern of non identity