Constructing a Magnetic Tweezers to Monitor RNA Translocation at the Single-Molecule Level

  • Desiree Salas
  • Veronika Gocheva
  • Marcelo NöllmannEmail author
Part of the Methods in Molecular Biology book series (MIMB, volume 1259)


Single-molecule methods have become an invaluable tool in the investigation of the mechanisms of nucleic-acid motors. Magnetic tweezers is a single-molecule manipulation technique that permits the real-time measurement of enzyme activities on single nucleic-acid molecules at high-resolution, high-throughput, and inherently constant force. Here, we describe several aspects of the implementation of magnetic tweezers, with special emphasis on the construction of a simple magnetic trap and, in particular, on the detailed description of image analysis methods to measure the extension changes in nucleic-acid molecules induced by protein activity. Finally, we carefully describe the steps involved in performing a full magnetic tweezers experiment.

Key words

Motors Nucleic-acid enzymes RNA Magnetic tweezers Single molecule Mechanochemistry 



We thank Francesco Pedaci and Antoine Le Gall for critical reading and very helpful comments. Financial support was provided by the Human Frontiers Science Program (M.N.) and the European Research Council (Starting Grant 260787 to M.N.).


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Desiree Salas
    • 1
    • 2
    • 3
  • Veronika Gocheva
    • 1
    • 2
    • 3
  • Marcelo Nöllmann
    • 1
    • 2
    • 3
    Email author
  1. 1.Centre de Biochimie StructuraleCNRS UMR5048MontpellierFrance
  2. 2.INSERM U1054MontpellierFrance
  3. 3.Universités Montpellier I et IIMontpellierFrance

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