Light-directed synthesis of high-density oligonucleotide arrays using semiconductor photoresists

High-density arrays of oligonucleotide probes are proving to be powerful new tools for large-scale DNA and RNA sequence analysis. A method for constructing these arrays, using light-directed DNA synthesis with photoactivatable monomers, can currently achieve densities on the order of 106 sequences/cm2. One of the challenges facing this technology is to further increase the volume, complexity, and density of sequence information encoded in these arrays. Here we demonstrate a new approach for synthesizing DNA probe arrays that combines standard solid-phase oligonucleotide synthesis with polymeric photoresist films serving as the photoimageable component. This opens the way to exploiting high-resolution imaging materials and processes from the microelectronics industry fur the fabrication of DNA probe arrays with substantially higher densities than are currently available.