A DNA SELF-ASSEMBLED MONOLAYER FOR THE SPECIFIC ATTACHMENT OF UNMODIFIED DOUBLE-STRANDED-DNA OR SINGLE-STRANDED-DNA

A novel method for DNA surface immobilization and a paradigm for the a ttachment of unmodified DNA of any length or sequence are described he rein. The development of a DNA self-assembled monolayer (DNA-SAM) that incorporates a DNA-thiol into a monolayer of inert alkane thiolates i s reported. This DNA-SAM specifically hybridized complementary oligonu cleotides while resisting the nonspecific adsorption of noncomplementa ry DNA and irrelevant proteins. Duplex DNA, having a single-stranded ' 'capture tail,'' specifically bound to the DNA-SAM if the sequence of the ''tail'' was complementary to DNA presented in the SAM. The sense strand of the hybridized duplex DNA could be covalently attached to th e surface by an enzymatic ligation reaction (leaving the anti-sense st rand dissociable). DNA-binding proteins specifically bound to these su rfaces only if their cognate sites were present in the duplex DNA.