Thermophoretic forces on DNA measured with a single-molecule spring balance

    Research output: Contribution to journalJournal articleResearchpeer-review

    336 Downloads (Pure)

    Abstract

    We stretch a single DNA molecule with thermophoretic forces and measure these forces with a spring balance: the DNA molecule itself. It is an entropic spring which we calibrate, using as a benchmark its Brownian motion in the nanochannel that contains and prestretches it. This direct measurement of the thermophoretic force in a static configuration finds forces up to 130 fN. This is eleven times stronger than the force experienced by the same molecule in the same thermal gradient in bulk, where the molecule shields itself. Our stronger forces stretch the middle of the molecule up to 80% of its contour length. We find the Soret coefficient per unit length of DNA at various ionic strengths. It agrees, with novel precision, with results obtained in bulk for DNA too short to shield itself and with the thermodynamic model of thermophoresis.
    Original languageEnglish
    JournalPhysical Review Letters
    Volume113
    Issue number26
    Pages (from-to)268301
    Number of pages5
    ISSN0031-9007
    DOIs
    Publication statusPublished - 2014

    Bibliographical note

    © 2014 American Physical Society

    Fingerprint Dive into the research topics of 'Thermophoretic forces on DNA measured with a single-molecule spring balance'. Together they form a unique fingerprint.

    Cite this