Oligonucleotide assembly using ph based electrode controlled hybridization

Abstract

Electrode controlled hybridization is used to change local pH and selectively assemble oligonucleotide complexes on the surface of a microelectrode array. The oligonucleotide complexes have sticky ends that provide locations for subsequent oligonucleotide complexes to hybridize. The order in which specific oligonucleotide complexes are joined together encodes information. Controlled activation of individual electrodes in the microelectrode array creates negative voltages that reduces a buffer solution and raises the pH in proximity to the electrodes. At higher pH levels double-stranded oligonucleotides de-hybridize. Nicks between oligonucleotide complexes and oligonucleotides anchored to the microelectrode array are closed creating covalent attachments. De-hybridized single-stranded oligonucleotides are removed leaving only the oligonucleotides connected to microelectrode array. Thus, during a given round of synthesis, oligonucleotide complexes are added only to the locations on the microelectrode array where the electrodes are not activated.