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Precipitin Arc / Line

Definition

The visible band of precipitate in an Ouchterlony plate where diffusing antigen and diffusing antibody meet. Its shape and relationship to adjacent arcs encodes species identity.

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...
Double Immunodiffusion (Ouchterlony)
A gel diffusion method in which both antigen and antibody diffuse toward each other from separate wells in agar. Precipitin bands form...
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 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....

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