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Double-immunodiffusion assay for detecting specific antibodies
1University of Maryland, Baltimore, Maryland, USA.
Double immunodiffusion owes its success to the unique nature of antibody-antigen interactions. When polyvalent antibodies with moderate-to-high intrinsic affinities are mixed with antigen at the right ratio (called the zone of equivalence) lattices of antibody-antigen complexes form and precipitate out of solution. When, as described in this unit, gradients of antigen and antibody are established by diffusion from adjacent wells in a bed of agar, a line of practically insoluble precipitation forms at the equivalence zone (precipitin lines).
Double immunodiffusion owes its success to the unique nature of antibody-antigen interactions. When polyvalent antibodies with moderate-to-high intrinsic affinities are mixed with antigen at the right ratio (called the zone of equivalence) lattices of antibody-antigen complexes form and precipitate out of solution. When, as described in this unit, gradients of antigen and antibody are established by diffusion from adjacent wells in a bed of agar, a line of practically insoluble precipitation forms at the equivalence zone (precipitin lines).
