Double Immunodiffusion (Ouchterlony)
Definition
A gel diffusion method in which both antigen and antibody diffuse toward each other from separate wells in agar. Precipitin bands form at equivalence. Band patterns reveal identity, partial identity, or non-identity between compared antigens.
Related terms
- Antiserum (Pl. Antisera)
- Blood serum from an animal (typically a rabbit) that has been immunised against the proteins of another species. It contains antibodies that...
- Equivalence Zone
- The range of antigen-to-antibody ratios at which binding sites on both molecules are maximally cross-linked, producing the largest lattice and the heaviest...
- Immunoelectrophoresis
- A two-step technique: proteins are first separated by electrophoresis in agar gel, then antiserum diffuses from a parallel trough and forms precipitin...
- Lattice Theory
- The structural explanation for precipitation proposed by Marrack in 1934. Multivalent antigens and bivalent antibodies can each bind more than one partner,...
- Precipitin
- An antibody that forms a visible precipitate when it reacts with its specific soluble antigen. The term is used interchangeably with precipitating...
- Precipitin Arc / Line
- The visible band of precipitate in an Ouchterlony plate where diffusing antigen and diffusing antibody meet. Its shape and relationship to adjacent...
- Precipitin Test
- A serological method in which an antiserum specific to one species' proteins is mixed with an extract of an unknown specimen. Formation...
- Ring Precipitation Test
- A technique in which antiserum is placed in a narrow capillary tube and antigen solution is layered carefully on top. A ring...
- Ring Precipitin Test
- A tube-based precipitin assay in which the antiserum is carefully underloaded beneath the sample; a ring of precipitate at the interface indicates...
- Spur Formation
- In Ouchterlony, a spur is formed when one arc curves beyond another due to an excess of a cross-reacting but non-identical antigen....
Explained in these topics
- Precipitation Reactions: Principles and ApplicationsA gel diffusion method in which both antigen and antibody diffuse toward each other from separate wells in agar. Precipitin bands form at equivalence. Band pat...
- Species of Origin: Precipitin and Ouchterlony TestsA gel-based assay in which both the antigen (test sample) and the antibody (antiserum) diffuse toward each other from separate wells cut in agar. A precipitin...