What is the purpose of double immunodiffusion?
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 principle of double diffusion?
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 is the outcome of too low or too high a concentration of antigen in double immunodiffusion?
Too low a concentration of antigen causes the precipitate to be located in the antigen well in double diffusion experiments, and too high a concentration pushes the position of equivalence into the antibody well.
Why is the ouchterlony test important?
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.
How does Ouchterlony double diffusion 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.
In which immunodiffusion do antibody and antigen diffuse in gel in double immunodiffusion?
Ouchterlony double diffusion
It is more commonly known as Ouchterlony double diffusion or passive double immunodiffusion. In this method, both the antigen and antibody diffuse independently through agar gel in two dimensions, horizontally and vertically.
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 difference between agglutination and precipitation?
The main difference between agglutination and precipitation is that agglutination is the formation of a solid mass by aggregating suspended particles in solution whereas precipitation is the formation of a solid mass as a result of a chemical reaction occur between two ionic components.