Progress in immunoassay technology.

Immunoassay is now the most widely used analytical technique in laboratory medicine embracing a vast repertoire of analytes and delivered through an increasingly diverse range of devices. This explosion of analytical techniques is complemented by an increasing knowledge base on the antigen antibody reaction that is being used to explore new and improved methodologies. Our knowledge of the molecular chemistry of the antigen antibody reaction coupled with the molecular biology of immunoglobulin expression has led to the development of antibody and antibody-like molecules with enhanced specificity, and reaction kinetics. These developments include novel fusion proteins, antibody mimics and antibodies that recognise antigen antibody complexes. The advances in the chemistry of the analytical systems are matched by the design of delivery vehicles: on the one hand the automated analyser that facilitates the analysis of large numbers of samples and on the other, the encapsulated, miniaturised device that enables an immunoassay to be performed at the point of care.