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Updated: May 11, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Torque spectroscopy of DNA: base-pair stability, boundary effects, backbending, and breathing dynamics
Florian C Oberstrass1, Louis E Fernandes, Paul Lebel
1Department of Bioengineering, Stanford University, Stanford, California 94305, USA.
Abstract:
Changes in global DNA linking number can be accommodated by localized changes in helical structure. We have used single-molecule torque measurements to investigate sequence-specific strand separation and Z-DNA formation. By controlling the boundary conditions at the edges of sequences of interest, we have confirmed theoretical predictions of distinctive boundary-dependent backbending patterns in torque-twist relationships. Abrupt torque jumps are associated with the formation and collapse of DNA bubbles, permitting direct observations of DNA breathing dynamics.
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