In vitro biological screening in discovery of hits & leads

The field of biological screening has evolved considerably since traditional medicine and serendipitous findings became more closely associated with technological advances in basic sciences at the end of the 19th and the beginning of the 20th century. This association became even more pronounced during the early 1990’s, when the parallel and combinatorial chemistry, as well as high-throughput biological screening revolution began. The concept of using a “high-throughput” paradigm for both chemistry and biology during drug discovery has advanced considerably in the last two decades. This chapter addresses the value and different aspects of in vitro biological screening in drug discovery, from definition of targets, through basic biological screening concepts, readout types and screening technologies, to reverse pharmacology, ‘mode of action’ studies and the role of biomarkers in drug discovery.