Patent ID: 7179591

Claim:
A method for the synthesis of combinatorial libraries of oligonucleotide arrays comprising: (a) providing a housing containing a unitary synthesis block, said unitary synthesis block including an array of microchannels enclosed within the unitary synthesis block having a first end and a second end of the microchannels, wherein each of the microchannels has an inner microchannel surface, the inner surface of each of the microchannels containing immobilized substrate molecules comprised of oligomeric or polymeric molecules thereon wherein the termini of said substrate molecules have protecting groups coupled thereto; (b) providing a light source and a mask for selectively illuminating microchannels in the array; (c) flowing a photoactivatable reagent through the array of microchannels from the first end to the second end while selectively illuminating at least a portion of the microchannels from an end thereof, to provide photoactivated reagent in the selectively illuminated microchannels; (d) removing protecting groups from the termini of the substrate molecules using the photoactivated reagent thereby forming deprotected substrate molecules in the selectively illuminated microchannels; (e) reacting the deprotected substrate molecules with one or more nucleoside monomers under conditions effective for coupling the nucleoside monomers with the deprotected substrate molecules; and (f) repeating steps (c) through (e) until a desired oligonucleotide array is formed within the microchannels.