immunodiffusion assay Ouchterlony double immunodiffusion assay 2013-11-13T14:40:32Z A technique for detecting antibody-antigen interactions, where antigens and antibodies are placed into separate wells cut into a gel matrix and allowed to diffuse towards each other. Where the diffusion fronts meet, if an antibody recognizes an antigen, they will bind, forming an immune complex. The immune complex precipitates in the gel to give a visible white line. JSmith MMO:0000438 agar gel double immunodiffusion measurement_method_ontology passive double immunodiffusion