title: Camera-based three-dimensional real-time particle tracking at kHz rates and Ångström accuracy.
abstract: Optical and magnetic tweezers are widely employed to probe the mechanics and activity of individual biomolecular complexes. They rely on micrometre-sized particles to detect molecular conformational changes from the particle position. Real-time particle tracking with Ångström accuracy has so far been only achieved using laser detection through photodiodes. Here we demonstrate that camera-based imaging can provide a similar performance for all three dimensions. Particle imaging at kHz rates is combined, with real-time data processing being accelerated by a graphics-processing unit. For particles that are fixed in the sample cell we can detect 3-Å-sized steps that are introduced by cell translations at rates of 10 Hz, while for DNA-tethered particles 5 Å steps at 1 Hz can be resolved. Moreover, 20 particles can be tracked in parallel with comparable accuracy. Our approach provides a simple and robust way for high-resolution tweezer experiments using multiple particles at a time.
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Dresden, 01062, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Huhle
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Dresden, 01062, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Klaue
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Dresden, 01062, Germany.
authors.forename: Hergen
authors.initials: H
authors.lastname: Brutzer
authors.affiliation: Institute for Molecular Cell Biology, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Daldrop
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Dresden, 01062, Germany.
authors.forename: Sihwa
authors.initials: S
authors.lastname: Joo
authors.affiliation: University of Cambridge, Cavendish Laboratory, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
authors.forename: Oliver
authors.initials: O
authors.lastname: Otto
authors.affiliation: University of Cambridge, Cavendish Laboratory, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
authors.forename: Ulrich F
authors.initials: UF
authors.lastname: Keyser
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Dresden, 01062, Germany.|Institute for Molecular Cell Biology, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Seidel