Electronic DNA Sequencing with Ion Channel Research

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This SGER proposal describes exploratory research into the technology and techniques required for fabrication of 'nanopores' (e.g. 5 to 100 nm). These nanopores will become part of a unique planar nanopipette for the study of single ion channels in biological cells - cells that need to form a gigaseal around the opening of the nanopore. In the future we will locate low-noise amplifiers and sensors millimeters from these nanopore openings formed in a multi-well chip. In the field of single channel recordings from individual ion channels the recording noise is an important limiting factor in characterizing the behavior of ion-specific channels in the presence of drugs. We plan to investigate nanopore techniques, such as E-beam, focus-ion beam (FIB) and field emission from a scanning transmission electron microscop. The results of our ion-channel research may be applied to the 'threading' of a polynucleotide, single-strand, DNA molecule through a nanopore under an applied electric field. As the DNA passes through the limiting aperture of an open nanopore, the flow of ions in the nanopore should be 'blocked' in a manner indicative of the molecular size and chemical properties of each nucleotide in the polynucleotide chain. Thus, we hope to utilize single channel recordings to determine electronically the direct sequence of the individual bases in a single-stranded DNA molecule, thereby opening the door to sequencing the human genome in hours rather than years as with capillary electrophoresis (CE) and ultra-thin slab gel techniques. Ion channel research will play an increasingly important role in understanding numerous diseases and processes in the cardiovascular system and the central nervous system. Diseases and disorders such as migraine, epilepsy, Alzheimer's, cardiac arrhythmias, cystic fibrosis, and hypertension have all been found to have ion channel involvement and drug therapies directed at these and other disorders are focused on ion channels.