Santa Cruz, CA, USA and Oxford¹, UK, 27 September 2010: Research published this week in Nature Nanotechnology shows a new method of enzyme²-controlled movement of a single strand³ of DNA⁴ through a protein nanopore. The paper, by researchers at the University of California Santa Cruz (UCSC), represents a key step towards nanopore sequencing of DNA strands⁵（线，绳索） . The publication describes the observation of single stranded⁶ DNA (ssDNA) as it translocates through a protein nanopore, alpha hemolysin（溶血素） (AHL). Movement of the ssDNA was controlled by polymerase（聚合酶） -facilitated replication of individual DNA molecules⁸. This movement could be initiated⁹ under electronic control. Polymerase activity was shown to be blocked in solution when the ssDNA was not at the nanopore opening, however capture of the strand by the pore removes a blocking strand of nucleotides（核苷酸） and allows the polymerase to function on the trapped strand.

UCSC researchers are collaborating¹⁰ with Oxford Nanopore Technologies Ltd in the development of a new generation of electronic, single-molecule⁷ DNA sequencing technology. In the 'strand sequencing' method, current through a nanopore is measured as a DNA polymer passes through that pore. Changes in this current are used to identify the DNA bases on the DNA molecule, in sequence. This paper addresses a key challenge for DNA strand sequencing: fine control of the translocation of the DNA strand through the nanopore, at a rate that is consistent and slow enough to enable accurate identification of individual DNA bases. The Nature Nanotechnology work shows for the first time that the motion of a strand can be controlled using electronic feedback（反馈） and that an enzyme can move a strand against a field while located on top of the nanopore.

"The techniques described in this paper are an advance towards electronic, single molecule DNA sequencing of DNA strands" said investigator¹¹ Professor Mark Akeson of the University of California, Santa Cruz. "Electronic control of DNA translocation through a protein nanopore is a scientific goal that we have strived（努力，奋斗） towards for years and these methods are now forming the basis for further work in our laboratories. We are excited by our collaboration¹² with Oxford Nanopore, whose parallel nanopore sensing strategy is impressive."