LIGAND ASSAYS - FROM ELECTROPHORESIS TO MINIATURIZED MICROARRAYS

The main developments in the ''ligand assay'' field in which I have be en involved are traced. These include the original development of ''fi rst generation'' competitive assays relying on radiolabeled analyte ma rkers; the development of the first ''second generation'', noncompetit ive (ultrasensitive) methods, which rely on the use of labeled (monocl onal) antibodies and high specific activity nonisotopic labels (leadin g to the transformation of the immunodiagnostic field in the 1980s); a nd the development of the first ''third generation'' miniaturized, chi p-based, microarray methods, which permit the simultaneous ultrasensit ive measurement of many analytes in the same small sample. The latter- applicable both to immunoassay and to DNA/RNA analysis-are likely to r evolutionize the diagnostic and pharmaceutical fields in the next deca de.