Simultaneous Single-Molecule Force and Fluorescence Sampling of DNA Nanostructure Conformations Using Magnetic Tweezers

Research paper by Felix E. Kemmerich, Marko Swoboda, Dominik J. Kauert, M. Svea Grieb, Steffen Hahn, Friedrich W. Schwarz, Ralf Seidel, Michael Schlierf

Indexed on: 11 Dec '15Published on: 03 Dec '15Published in: Nano Letters


We present a hybrid single-molecule technique combining magnetic tweezers and Förster resonance energy transfer (FRET) measurements. Through applying external forces to a paramagnetic sphere, we induce conformational changes in DNA nanostructures, which are detected in two output channels simultaneously. First, by tracking a magnetic bead with high spatial and temporal resolution, we observe overall DNA length changes along the force axis. Second, the measured FRET efficiency between two fluorescent probes monitors local conformational changes. The synchronized orthogonal readout in different observation channels will facilitate deciphering the complex mechanisms of biomolecular machines.

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