Nanopore Sequencing Continues To Advance

Two research groups have brought nanopore DNA sequencing closer to reality. These scientists are among those trying to sequence DNA more rapidly and inexpensively than is currently possible by identifying nucleotides one by one as they traverse a tiny hole. This approach could aid personalized medicine, which aims to tailor drugs or medical treatments to people on the basis of their individual genetic makeup. Hagan Bayley of the University of Oxford and coworkers recently showed that all four DNA nucleotides plus 5-methylcytosine can be detected by directing free nucleotides through nanopores formed by α-hemolysin protein. Now, they find a similar ability to discriminate among nucleotides reliably when an intact DNA strand passes through an α-hemolysin pore mutated to enhance detection currents (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0901054106). Meanwhile, Xinsheng Sean Ling's group at Brown University has shown that a magnet can be used to control the rate at which a DNA strand tethered to a magnetic bead passes through a silicon-based nanopore (Nanotechnology, DOI: 10.1088/0957-4484/20/18/185101). This strategy, in which DNA is under tension, could enhance nucleotide discrimination and permit multiple DNA segments to be read simultaneously, speeding up analysis.