Mechanical opening of DNA by micromanipulation and force measurement
C. R. Physique 3, 585 (2002)
U. Bockelmann, B. Essevaz-Roulet, Ph. Thomen and F. Heslot,In this paper we summarize part of our work on the mechanical unzipping of DNA. We have prepared molecular constructions which allow us to attach the two complementary strands of one end of a single DNA molecule of the bacteriophage l separately to a glass microscope slide and a microscopic bead. In a first series of experiments, a soft microneedle acting as a force sensor is attached to the bead and its deflection is measured with an optical microscope. In a second series, we use an optical trapping interferometer to capture the bead and to measure its displacement to nm resolution. The sample is slowly displaced with respect to the force measurement device, leading to a progressive opening of the double helix. The force measured during this mechanical opening shows a characteristic variation which is related to the base pair sequence of the DNA molecule.
Dans la même rubrique :
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- Single molecule study of DNA conductivity in aqueous environment
- Unravelling the Mechanism of RNA-Polymerase Forward Motion by Using Mechanical Force.
- Single-molecule study of RuvAB-mediated Holliday-junction migration
- Dynamics of the DNA duplex formation studied by single molecule force measurements
- Rotational Drag on DNA : A Single Molecule Experiment
- Unzipping DNA with Optical Tweezers : High Sequence Sensitivity and Force Flips
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