Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
A laboratory technique used to detect the type and quantity of a substance, such as an abnormal immunoglobulin, for which an antibody is available.
A test method in which an antigen and antibody are placed in a gel, where they diffuse toward each other. When they meet, a precipitate is formed.