A gel-diffusion, antibody-antigen precipitation test that depends on horizontal diffusion from two or more opposite sources. An agar slab is prepared and two or more wells are cut in it. One (A) is filled with an aqueous suspension of antibody molecules, while each of the other wells (B and C in the illustration here) is filled with a different antigen preparation. The antigen and antibody molecules diffuse toward each other and eventually interact, forming curved precipitation lines. In example I, the antigens in wells B and C are different. In II, well B contains a single antigen and well C two antigens, one identical to that in B. See Chronology, 1948, Ouchterlony.
Subjects: Genetics and Genomics — Chemistry.