A high-speed magnetic tweezer beyond 10,000 frames per second

Lansdorp, Bob M.; Tabrizi, Sarah J.; Dittmore, Andrew; Saleh, Omar A.

doi:10.1063/1.4802678

Cited by 79 publications

(78 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2-6, 8, 9, 12, 13 Many approaches to active, three-dimensional (3D) drift correction track the position of a fiducial marker adhered to or built into the surface of the sample slide, which indirectly gives the position of the stage. 1,8,9,[12][13][14][15] Stabilization is then achieved by adjusting a piezo stage to compensate for drift via a feedback loop. In particular, back-focal-plane interferometry (BFPI) employs a laser focused directly on a built-in fiducial marker.…”

mentioning

confidence: 99%

Active drift stabilization in three dimensions via image cross-correlation

Koo

Setru

Mochrie

2013

Review of Scientific Instruments

View full text Add to dashboard Cite

By monitoring stage drift via the normalized cross-correlation of an image of a stuck bead, obtained in real-time, with an out-of-focus "template" image of a similar immobile bead, stored in memory, we implement a simple approach to actively stabilize drift in all three dimensions for existing video microscopy setups. We demonstrate stability to 0.0062 nm along the Z-axis and 0.0031 nm along the X- and Y-axes for long (100 s) timescales.

show abstract

mentioning

confidence: 99%

Active drift stabilization in three dimensions via image cross-correlation

Koo

Setru

Mochrie

2013

Review of Scientific Instruments

View full text Add to dashboard Cite

show abstract

“…Although the post-processing option is not limited by the instantaneously available processing power, it has its limits in conventional PC hardware memory and camera interfaces, as these cameras can record videos at several hundred Hz and therefore produce large amounts of data. Parallel handling of multiple beads from a single frame [37,38] is also becoming increasingly popular, as is outsourcing computationally demanding processing steps to graphics processing units (GPUs) [39]. Figure 12.3 depicts a general flow diagram of our tracking algorithm implementation.…”

Section: Tracking Algorithmmentioning

confidence: 99%

“…Our current setup allows parallel tracking of up to ten beads without exhausting the available PC resources. Further acceleration of these calculations can be achieved by GPU processing that is highly optimized for parallelization [39].…”

Section: Tracking Algorithmmentioning

confidence: 99%

Measuring Two at the Same Time: Combining Magnetic Tweezers with Single-Molecule FRET

Swoboda

Grieb

Hahn

et al. 2014

Experientia Supplementum

View full text Add to dashboard Cite

Molecular machines are the workhorses of the cell that efficiently convert chemical energy into mechanical motion through conformational changes. They can be considered powerful machines, exerting forces and torque on the molecular level of several piconewtons and piconewton-nanometer, respectively. For studying translocation and conformational changes of these machines, fluorescence methods, like FRET, as well as "mechanical" methods, like optical and magnetic tweezers, have proven well suited over the past decades. One of the current challenges in the field of molecular machines is gaining maximal information from single-molecule experiments by simultaneously measuring translocation, conformational changes, and forces exerted by these machines. In this chapter, we describe the combination of magnetic tweezers with single-molecule FRET for orthogonal simultaneous readout to maximize the information gained in single-molecule experiments.

show abstract

“…In addition, to ascertain dynamical or force-induced conformational changes, the length of the biomolecular tether under tension is determined. For this, camera-based particle tracking is typically applied (3)(4)(5)(6)(7). Magnetic tweezers have been widely used to study the mechanical properties of biological (8,9) and synthetic (10) polymers, to investigate the response of DNA upon supercoiling (1,(11)(12)(13)(14)(15), and to resolve the real-time dynamics of DNA-interacting proteins, such as DNA-binding proteins (16)(17)(18), enzymes that regulate DNA supercoiling (19)(20)(21), and molecular motors (22)(23)(24)(25)(26)(27).…”

Section: Introductionmentioning

confidence: 99%

Extending the Range for Force Calibration in Magnetic Tweezers

Daldrop

Brutzer

Huhle

et al. 2015

Biophysical Journal

View full text Add to dashboard Cite

Magnetic tweezers are a wide-spread tool used to study the mechanics and the function of a large variety of biomolecules and biomolecular machines. This tool uses a magnetic particle and a strong magnetic field gradient to apply defined forces to the molecule of interest. Forces are typically quantified by analyzing the lateral fluctuations of the biomolecule-tethered particle in the direction perpendicular to the applied force. Since the magnetic field pins the anisotropy axis of the particle, the lateral fluctuations follow the geometry of a pendulum with a short pendulum length along and a long pendulum length perpendicular to the field lines. Typically, the short pendulum geometry is used for force calibration by power-spectral-density (PSD) analysis, because the movement of the bead in this direction can be approximated by a simple translational motion. Here, we provide a detailed analysis of the fluctuations according to the long pendulum geometry and show that for this direction, both the translational and the rotational motions of the particle have to be considered. We provide analytical formulas for the PSD of this coupled system that agree well with PSDs obtained in experiments and simulations and that finally allow a faithful quantification of the magnetic force for the long pendulum geometry. We furthermore demonstrate that this methodology allows the calibration of much larger forces than the short pendulum geometry in a tether-length-dependent manner. In addition, the accuracy of determination of the absolute force is improved. Our force calibration based on the long pendulum geometry will facilitate high-resolution magnetic-tweezers experiments that rely on short molecules and large forces, as well as highly parallelized measurements that use low frame rates.

show abstract

A high-speed magnetic tweezer beyond 10,000 frames per second

Cited by 79 publications

References 27 publications

Active drift stabilization in three dimensions via image cross-correlation

Active drift stabilization in three dimensions via image cross-correlation

Measuring Two at the Same Time: Combining Magnetic Tweezers with Single-Molecule FRET

Extending the Range for Force Calibration in Magnetic Tweezers

Contact Info

Product

Resources

About