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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-based assay in which both the antigen (test sample) and the antibody (antiserum) diffuse toward each other from separate wells cut...
Precipitin test
A species-confirmation test that adds species-specific antiserum to a stain extract; a visible precipitate forms only when the target protein is present....
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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