IBM Sets Out to Build a Nanoscale DNA Sequencer

IBM Research aims to build a nanoscale DNA sequencer, which if succesful could improve throughput and reduce cost to $100–$1,000 per genome sequenced. The scientists’ technique will analyze genetic code by passing DNA strands through nano-sized holes in silicon-based chips, or what they’re calling a DNA transistor.

The challenge is to slow and control the motion of the DNA through the hole so that the reader can accurately decode what is in the DNA. A team of IBM scientists from four fields—nanofabrication, microelectronics, physics, and biology—are converging to master the technique that threads a long DNA molecule through a three-nanometer wide hole, known as a nanopore, in a silicon chip. As the molecule is passed through the nanopore, it is ratcheted one unit of DNA at a time, as an electrical sensor reads the DNA.

IBM scientists believe that they have a unique approach to controlling the rate at which a DNA strand moves through the nanoscale aperture. They have developed a device consisting of a multilayer metal/dielectric nano-structure that contains the nanopore. Voltage biases between the electrically addressable metal layers will modulate the electric field inside the nanopore. This device utilizes the interaction of discrete charges along the backbone of a DNA molecule with the modulated electric field to trap DNA in the nanopore.

By cyclically turning on and off these gate voltages, scientists showed theoretically and computationally and expect to be able to prove experimentally, the plausibility of moving DNA through the nanopore at a rate of one nucleotide per cycle. IBM researchers believe that this rate would make DNA readable.

“The technologies that make reading DNA fast, cheap, and widely available have the potential to revolutionize biomedical research and herald an era of personalized medicine,” remarks IBM research scientist Gustavo Stolovitzky. “Ultimately, it could improve the quality of medical care by identifying patients who will gain the greatest benefit from a particular medicine and those who are most at risk of adverse reaction.”