A method is disclosed for the direct synthesis of double stranded DNA
molecules of a variety of sizes and with any desired sequence. The DNA
molecule to be synthesis is logically broken up into smaller overlapping
DNA segments. A maskless microarray synthesizer is used to make a DNA
microarray on a substrate in which each element or feature of the array
is populated by DNA of a one of the overlapping DNA segments. The DNA
segments are released from the substrate and held under conditions
favoring hybridization of DNA, under which conditions the segments will
spontaneously hybridize together to form the desired DNA construct. This
method makes possible the remote assembly of DNA sequence, through a
process analogous to facsimile transmission of documents, since the
information on DNA to be made can be transmitted remotely to an
instrument which can then synthesize any needed DNA sequence from the
information.