FABRICATION OF PATTERNED DNA SURFACES

Two photolithographic methods are described for the formation of patte rned single or multiple DNA species on SiO2 substrates, In the first a pproach, substrates are treated with a photochemically labile organosi lane monolayer film. Irradiation of these surfaces with patterned deep UV (193 nm) light results in patterned chemically reactive groups whi ch are then reacted with heterobifunctional crosslinking molecules, Co valent attachment of modified synthetic DNA oligomers to the crosslink er results in stable DNA patterns, Alternatively, a photoresist is spi n-coated over a silane film which had been previously modified with th e hetero-bifunctional crosslinker, Upon patterned irradiation and subs equent development, the underlying cross-linker-modified layer is reve aled, and is then reacted with a chemically modified DNA, Feature dime nsions to 1 micron are observed when a single fluorescent DNA is attac hed to the surface, By performing sequential exposures, we have succes sfully immobilized two distinguishable DNA oligomers on a single surfa ce, Synthetic DNA immobilized in this manner retains the ability to hy bridize to its complementary strand, suggesting that these approaches may find utility in the development of miniaturized DNA-based biosenso rs.