A new method of parallel synthesis suitable for making microarrays of biomolecules has been developed. The method involves the use of novel solution chemistry and programmable photolithographic instruments. The chemistry described herein lies in its use of photo-generated reagents to affect otherwise conventional synthesis chemistry. The photolithographic instrument consists of a digital light projector that is capable of generating photolithographic patterns directly from a computer. We will describe our results on the synthesis of oligonucleotides and peptides using photogenerated acids.

Our method of using photo-generated reagents enables light-initiation of conventional synthesis reactions. This new approach takes advantage of well-established synthesis procedures and materials and thus, promises simple, flexible, high quality and low cost parallel synthesis of microarrays of oligonucleotides, peptides and diverse molecular sequences. The use of a digital light projector makes light-directed synthesis flexible and eliminates the need for expensive photomask-based photolithographic equipment and associated cleanroom facilities.

Using the new method as a technological foundation we are currently developing a programmable maskless automated microarray synthesiser that is affordable and technically manageable by most laboratories interested in biochips. The availability of such an instrument would significantly accelerate the processes of gene analysis and the development of gene-based applications.