Nanofabricated quartz cylinders for angular trapping: DNA supercoiling torque detection

Nat Methods. 2007 Mar;4(3):223-5. doi: 10.1038/nmeth1013. Epub 2007 Feb 25.


We designed and created nanofabricated quartz cylinders well suited for torque application and detection in an angular optical trap. We made the cylinder axis perpendicular to the extraordinary axis of the quartz crystal and chemically functionalized only one end of each cylinder for attachment to a DNA molecule. We directly measured the torque on a single DNA molecule as it underwent a phase transition from B-form to supercoiled P-form.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • DNA / chemistry*
  • DNA / ultrastructure
  • Elasticity
  • Electrochemistry / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Lasers*
  • Micromanipulation / instrumentation*
  • Micromanipulation / methods
  • Nanostructures / chemistry
  • Nanotechnology / instrumentation*
  • Nucleic Acid Conformation
  • Quartz / chemistry*
  • Stress, Mechanical
  • Torque
  • Transducers*


  • Quartz
  • DNA