ABSTRACT
Miniaturization of assays is one of the major forces driving improved productivity in early drug discovery [14,15]. New drug development technologies and the explosion in genetic data as a result of the Human Genome Project have driven the development of miniaturized test beds or “biochips” for genetic analysis based on microarrays of nucleic acid sequences. These biochips encompass a very diverse array of technologies and applications. Imprinted with several hundred different nucleic acid sequences, biochips use electro-optical means of addressing applications ranging from expression analysis to genotyping and mutation screening [16,17]. Biochips integrated into sample processing, metering, measuring, mixing, and sorting systems have laid the foundation for miniaturized “sample to answer” systems. The first generation of biochips is focused on surface anchored oligonucleotides and oligopeptides whose information content is dictated by the four-character nucleotide language of the DNA or the 20-character language of amino acids. Furthermore, the single-stranded DNA oligonucleotides are limited in their information content and applications, as they do not provide information on DNA-protein and other interactions [18].
