ABSTRACT
Antibodies have found many applications in biotechnology and clinical medicine, including diagnostics assays, environmental testing, food testing, process monitoring and separations. In all cases the antibody is employed as a molecular recognition element that binds specifically to its antigen with high affinity. Actually the term antigen is sort of a misnomer because the mentioned applications are invariably performed in vitro, far removed from the animal which produced the antibodies. Instead, we shall refer to the antigen as the analyte in the case of immunoassays and as the ligand in the case of chromatography and other separations. In most instances the antibody is immobilized to a solid support-usually a bead or a planar surface -which provides the means for separating the antibody-analyte (or antibody-ligand) complex from unbound antigen and impurities in the sample. Interestingly, this partitioning step is required by both immunoassays and separations-for purposes of quantification in the former and as a means of purification in the latter.
