In this proof of principle the authors use magnetic tweezers to unzip a DNA hairpin and then measure the molecule extension during rezipping in the presence of oligomers that transiently block the rezipping process. The extent of these blockages allows them to determine the DNA sequence.

Paper: Single-molecule mechanical identification and sequencing

Ding F., Manosas M., Spiering M.M., Benkovic S.J., Bensimon D., Allemand J-F., & Croquette V. Nature Methods, published online: 11 March 2012 | doi:10.1038/nmeth.1925

Editorial: Magnetic Sequencing

Sten Linnarsson, Nature Methods 9, 339–341 (2012) doi:10.1038/nmeth.1934

Single-molecule DNA sequencing takes an important step in a surprising new direction with a sequence-detection method based on magnetic tweezers.