ABSTRACT
Immunoglobulins are a special kind of proteins that function as antibodies. They bind specically to “foreign” substances, the antigens. Because of their high selectivity and specicity, immunoglobulins are excellent probes to detect viruses (e.g., hepatitis or HIV), hormones (e.g., the pregnancy hormone), allergens, and pathogens. In many of such diagnostic test systems, the immunoproteins are immobilized to solid surfaces to increase their local concentration and to facilitate the visualization of the antibody-antigen complexes. The most common immobilization method is physical adsorption. However, adsorption may induce structural changes in the protein and a decreased accessibility of the antigen-binding sites, both resulting in a loss of immunological activity.
