Calibration of optical tweezers with differential interference contrast signals

Capitanio, Marco; Romano, G.; Ballerini, R.; Giuntini, M.; Pavone, Francesco S.; Dunlap, David; Finzi, Laura

doi:10.1063/1.1460929

Cited by 94 publications

(63 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus it is expected that trap stiffness will not depend on the distance of the bead to the surface when a water-immersion objective is used. 13 In most optical-trapping experiments it is important to know the exact trap stiffness to be able to quantify forces. It is therefore essential to know the full dependence of the optical-trap stiffness on the distance to the surface.…”

Section: Introductionmentioning

confidence: 99%

Optical trap stiffness in the presence and absence of spherical aberrations

et al. 2006

View full text Add to dashboard Cite

Optical traps are commonly constructed with high-numerical-aperture objectives. Oil-immersion objectives suffer from spherical aberrations when used for imaging in aqueous solutions. The effect of spherical aberrations on trapping strength has been modeled by approximation, and only a few experimental results are available in the case of micrometer-sized particles. We present an experimental study of the dependence of lateral and axial optical-trap stiffness on focusing depth for polystyrene and silica beads of 2 m diameter by using oil-and water-immersion objectives. We demonstrate a strong depth dependence of trap stiffness with the oil-immersion objective, whereas no depth dependence was observed with the water-immersion objective.

show abstract

Section: Introductionmentioning

confidence: 99%

Optical trap stiffness in the presence and absence of spherical aberrations

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Flow silica beads diluted 1/1,000 in phosphate buffer and seal the flow chamber with silicon grease. Trap one bead in each trap and calibrate the traps using the power spectrum method 18 . 3.…”

Section: Optical Tweezers Setup With Nanometer Stabilitymentioning

confidence: 99%

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions

Mónico

Belcastro

Vanzi

et al. 2014

JoVE

View full text Add to dashboard Cite

The paper describes the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method offers the opportunity of investigating interactions occurring in solution (thus avoiding problems due to closeby surfaces as in other single molecule methods), controlling the DNA extension and tracking interaction dynamics as a function of both mechanical parameters and DNA sequence. The methods for establishing successful optical trapping and nanometer localization of single molecules are illustrated. We illustrate the experimental conditions allowing the study of interaction of lactose repressor (lacI), labeled with Atto532, with a DNA molecule containing specific target sequences (operators) for LacI binding. The method allows the observation of specific interactions at the operators, as well as one-dimensional diffusion of the protein during the process of target search. The method is broadly applicable to the study of protein-DNA interactions but also to molecular motors, where control of the tension applied to the partner track polymer (for example actin or microtubules) is desirable. Video LinkThe video component of this article can be found at

show abstract

“…This high-NA geometry sets stringent aberration requirements that limit applicable sample chambers. The available working distance (a few hundred microns) sets a physical limit to the realizable axial trapping range even when aberrations are minimized (e.g., by adaptive correction [3], or by replacing the oil-immersion with water-immersion objectives [4,5]). This is a pity, since lower aberration sensitivity and a longer working distance can provide the experimentalist with a wider latitude for optical trapping and manipulation, such as when selecting or designing sample chambers and adding auxiliary instrumentation.…”

Section: Introductionmentioning

confidence: 99%

Dynamic axial stabilization of counter-propagating beam-traps with feedback control

Tauro¹,

Bañas²,

Palima³

et al. 2010

Opt. Express

View full text Add to dashboard Cite

Optical trapping in a counter-propagating (CP) beam-geometry provides unique advantages in terms of working distance, aberration requirements and intensity hotspots. However, its axial performance is governed by the wave propagation of the opposing beams, which can limit the practical geometries. Here we propose a dynamic method for controlling axial forces to overcome this constraint. The technique uses computervision object tracking of the axial position, in conjunction with softwarebased feedback, for dynamically stabilizing the axial forces. We present proof-of-concept experiments showing real-time rapid repositioning coupled with a strongly enhanced axial trapping for a plurality of particles of varying sizes. We also demonstrate the technique's adaptability for real-time reconfigurable feedback-trapping of a dynamically growing structure that mimics a continuously dividing cell colony. Advanced implementation of this feedback-driven approach can help make CP-trapping resistant to a host of perturbations such as laser fluctuations, mechanical vibrations and other distortions emphasizing its experimental versatility.

show abstract

Calibration of optical tweezers with differential interference contrast signals

Cited by 94 publications

References 19 publications

Optical trap stiffness in the presence and absence of spherical aberrations

Optical trap stiffness in the presence and absence of spherical aberrations

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions

Dynamic axial stabilization of counter-propagating beam-traps with feedback control

Contact Info

Product

Resources

About