What is Ouchterlony double diffusion technique?
Ouchterlony double immunodiffusion (also known as passive double immunodiffusion) is an immunological technique used in the detection, identification and quantification of antibodies and antigens, such as immunoglobulins and extractable nuclear antigens.
What is the reaction of Ouchterlony double diffusion?
In double immunodiffusion, both the antibody and antigen are allowed to diffuse into the gel. After application of the reactants in their respective compartments, the antigen and the antibody diffuse toward each other in the common gel and a precipitate is formed at the place of equivalence.
What is an Ouchterlony assay?
The immunodiffusion (ID) test, also called the Ouchterlony test, allows antigen detection. Immunodiffusion refers to the movement of the antigen or antibody or both antigen and antibody molecules in a diffusion support medium.
What are some limitations of Ouchterlony?
In the absence of staining, the Ouchterlony double immunodiffusion assay is sensitive to 100ug/ml of specific antibody, however a limitation of the technique is that is requires high concentrations of both antigen and antibody and are relatively insensitive to antibodies with low affinities (Hornbeck 1991).
What is zone of equivalence?
: the part of the range of possible proportions of interacting antibody and antigen in which neither or but small traces of both remain uncombined in the medium.
What is the principle of double diffusion assay?
Principle: When soluble antigen and antibody samples are placed in adjacent wells in agarose gel, they diffuse radially into the agarose gel and set up two opposing concentration gradients between the wells.
What are the limitations of ouchterlony?
How Ouchterlony double diffusion be helpful in evolutionary studies?
In Ouchterlony double diffusion, both antigen and antibody are allowed to diffuse into the gel. This technique can be used to test the similarity between antigens, for example in a study of evolution. The pattern of lines that form can be interpreted to determine whether the antigens are same or different.
What is equivalence in immunology?
What is Postzone phenomenon?
Postzone phenomenon is defined as a false-negative test resulting from high antigen titre, which interferes with the formation of the antigen-antibody lattice, necessary to visualize a positive test.
Is ouchterlony qualitative or quantitative?
Although there are now more sensitive and quantitative methods of detecting antibody-antigen interactions, the Ouchterlony test provides a rapid and qualitative way of determining whether an antiserum has antibodies against a particular antigen.