ABSTRACT
In the modern world the detection of infectious agents is often very complex. Only 10 to 15 years ago the major means for detecting viral infections were the cultivation of virus in tissues
in vitro
or the identification of a specific immunoresponse to the virus infection, which typically involved the detection of antibodies by using two simple and popular formats — enzyme immunoassay and radioimmunoassay. Today, however, diagnostics has become one of the most dynamic research areas involving the development of many different approaches such as molecular diagnostics or detection of nucleic acids, chip technology or microarray technology, molecular sensors, rapid assays, and noninvasive technologies for detection of antibodies in several different body fluids other than blood. All of these new developments, however, have not changed the fact that serodiagnostics or antibody detection remains one of most important diagnostic subject areas. The most essential component of serodiagnostic assays is the antigen used as a target responsible for specific antibody binding. For many years the development of diagnostic assays for the detection of diseasespecific antibodies depended exclusively on the availability of natural antigens obtained from biological specimens such as body fluid, stool, or sputum, or from
in vitro
propagation from infected human materials.
