Immunodiffusion
Jump to navigation
Jump to search
Introduction
Immunodiffusion reactions are diagnostic tests that use the diffusion of particles through a medium (such as agar) to measure:
- Relative concentrations of antibodies/antigens
- Relative purity of an antigen preparation
There are two types of immunodiffusion reaction, both being carried out on a semisolid medium:
- Radial immunodiffusion: also known as the Mancini method. The medium is prepared with a suitable dilution of antiserum and the antigen sample placed on top and allowed to diffuse. As diffusion takes place, large insoluble complexes form creating a ring of precipitation (precipitin). By comparing the area of the ring with a standard curve, the concentration of the antigen sample can be determined.
- Double immunodiffusion: also known as the Ouchterlony method. Antigen and antibody preparations are placed on the medium and both allowed to diffuse radially from the wells towards each other. This establishes a concentration gradient, forming an area of equivalence and line of precipitin.
 |
This article has been peer reviewed but is awaiting expert review. If you would like to help with this, please see more information about expert reviewing. |
|
Originally funded by the RVC Jim Bee Award 2007 |