In most societies the medical field is undergoing a dramatic reorientation.

Fundamentally new technologies in diagnosis and therapy, as well as the extension of life expectations, have increased health costs to an extent that now nears the limits of acceptability. One consequence has been a reevaluation of the need for and duration of each individual hospitalization. For diagnostic laboratories, results must now be obtained rapidly in order to include them in therapeutic decisions. Furthermore, therapeutic approaches to the control of infectious agents, limited by the number of therapeutic compounds available and by the growing perception of multiresistant agents, now require improvement in the precision of diagnostic approaches. The necessity for maximal reduction of the risk of infection by the development of appropriate pharmaceutical products demands even higher levels of sensitivity in diagnostic tests.

Today’s highly purified antigens—often from recombinantly generated antigens or peptides, monoclonal or recombinant antibodies, and more sensitive signal-production and signal-detection systems—have greatly advanced immunologically based detection methodology. However, this approach has biological limits that further enhancement of sensitivity cannot breach. Fortunately, nucleic acids have now been quite successfully added to the spectrum of diagnostic targets. Recombinant-produced antigens and the integration of microelectronics and microfluidics offer new perspectives and possibilities.