DNA Biochips - past, present, and future: An overview

Drug discovery is a complex and costly process, with greater than 99% of the investigated experimental compounds discarded as failures. Only a handful of the molecules evaluated as part of the discovery and preclinical phases reach the marketplace [1]. In the current economic climate, the pharmaceutical industry is faced with the double-edged dilemma of increased research and development costs and a decline in the number of novel therapeutics dispensed to the public. The main consequence of this is that the industry has been forced to devise and adapt methodologies that increase the number of new drug candidates in the pipeline, within a much shorter time frame [2]. In the drug discovery process, the identification of viable drug target for a therapeutic area of interest is of key importance [3]. This target is invariably a protein whose function or dysfunction is implicated in the pathology or progression of the disease, for example, a growth factor. A wellcharacterized example is the epidermal growth factor (EGF) receptor family. Interaction of the extracellular EGF ligand with its receptor results in a signal transduction cascade, ultimately leading to cell division, the synthesis of new proteins, and tumor progression.