Methods and devices based upon a novel form of nucleic acid duplex on a surface

Abstract

The present invention relates to simple method to fabricate DNA hybridization devices based upon adsorptive attachment of oligonucleotides to a positively charged surface. Such adsorbed oligonucleotide probes form a densely packed monolayer, which retains capacity for base-pair specific hybridization with a solution state nucleic acid target strand to form the duplex. However, both strand dissociation kinetics and the rate of DNase digestion suggest on symmetry grounds that solution-state nucleic acid binds to such adsorbed oligonucleotides to form a highly asymmetric and unwound duplex, with structural details that are substantially different from that known for the Watson-Crick DNA duplex. This novel nucleic acid duplex form can serve as the basis for a new class of hybridization device and methods for their use. It is also disclosed that new methods of nucleic acid duplex detection can be developed which are based upon the interaction of enzymes and dye labels with the unique structural characteristics of the non-helical duplex described herein. Preferred implementations of the invention include DNA microarrays, bead-based nucleic acid analysis, microelectronic devices to detect nucleic acid hybridization and more traditional methods of laboratory analysis, including hybridization on membranous and other solid supports.