1
|
Gómez-Viloria I, Nodar Á, Molezuelas-Ferreras M, Olmos-Trigo J, Cifuentes Á, Martínez M, Varga M, Molina-Terriza G. On-Axis Optical Trapping with Vortex Beams: The Role of the Multipolar Decomposition. ACS PHOTONICS 2024; 11:626-633. [PMID: 38405395 PMCID: PMC10885202 DOI: 10.1021/acsphotonics.3c01499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 02/27/2024]
Abstract
Optical trapping is a well-established, decades old technology with applications in several fields of research. The most common scenario deals with particles that tend to be centered on the brightest part of the optical trap. Consequently, the optical forces keep the particle away from the dark zones of the beam. However, this is not the case when a focused doughnut-shaped beam generates on-axis trapping. In this system, the particle is centered on the intensity minima of the laser beam and the bright annular part lies on the periphery of the particle. Researchers have shown great interest in this phenomenon due to its advantage of reducing light interaction with trapped particles and the intriguing increase in the trapping strength. This work presents experimental and theoretical results that extend the analysis of on-axis trapping with light vortex beams. Specifically, in our experiments, we trap micron-sized spherical silica (SiO2) particles in water and we measure, through the power spectrum density method, the trap stiffness constant κ generated by vortex beams with different topological charge orders. The optical forces are calculated from the exact solutions of the electromagnetic fields provided by the generalized Lorentz-Mie theory. We show a remarkable agreement between the theoretical prediction and the experimental measurements of κ. Moreover, our numerical model gives us information about the electromagnetic fields inside the particle, offering valuable insights into the influence of the electromagnetic fields present in the vortex beam trapping scenario.
Collapse
Affiliation(s)
- Iker Gómez-Viloria
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Álvaro Nodar
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Martín Molezuelas-Ferreras
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Jorge Olmos-Trigo
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Ángel Cifuentes
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Miriam Martínez
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
| | - Miguel Varga
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
- Donostia
International Physics Center, Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain
| | - Gabriel Molina-Terriza
- Centro
de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain
- Donostia
International Physics Center, Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain
- IKERBASQUE,
Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
| |
Collapse
|
2
|
Malinowska AM, van Mameren J, Peterman EJG, Wuite GJL, Heller I. Introduction to Optical Tweezers: Background, System Designs, and Applications. Methods Mol Biol 2024; 2694:3-28. [PMID: 37823997 DOI: 10.1007/978-1-0716-3377-9_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Optical tweezers are a means to manipulate objects with light. With the technique, microscopically small objects can be held and steered, allowing for accurate measurement of the forces applied to these objects. Optical tweezers can typically obtain a nanometer spatial resolution, a picoNewton force resolution, and a millisecond time resolution, which makes the technique well suited for the study of biological processes from the single-cell down to the single-molecule level. In this chapter, we aim to provide an introduction to the use of optical tweezers for single-molecule analyses. We start from the basic principles and methodology involved in optical trapping, force calibration, and force measurements. Next, we describe the components of an optical tweezers setup and their experimental relevance. Finally, we will provide an overview of the broad applications in context of biological research, with the emphasis on the measurement modes, experimental assays, and possible combinations with fluorescence microscopy techniques.
Collapse
Affiliation(s)
- Agata M Malinowska
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Joost van Mameren
- Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Gijs J L Wuite
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Iddo Heller
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
3
|
Mphuthi N, Bell T, Mabena CM. Effect of aberrations on the beam quality factor of Hermite-Gauss beams. OPTICS EXPRESS 2023; 31:39379-39395. [PMID: 38041261 DOI: 10.1364/oe.502925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/13/2023] [Indexed: 12/03/2023]
Abstract
The effect of aberrations on the beam quality factor (M2) of Hermite-Gauss (HG) beams is examined. Using the method of moments, we derive closed-form analytical expressions of M2 due to astigmatism and spherical aberration. Our analysis reveals that the radius of the HG beams plays a significant role in determining the effect of the aberrations on M2. For each aberration, we establish a critical width that separates the region where M2 changes infinitesimally from the region where it changes sharply. The analytical results are validated through numerical simulations.
Collapse
|
4
|
Chen Z, Kuang T, Han X, Li G, Zeng W, Xiong W, Xiao G, Luo H. Differential displacement measurement of the levitated particle using D-shaped mirrors in the optical tweezers. OPTICS EXPRESS 2022; 30:30791-30798. [PMID: 36242176 DOI: 10.1364/oe.468264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 07/29/2022] [Indexed: 06/16/2023]
Abstract
Displacement measurement using a D-shaped mirror is a key technology in optical tweezers, which have emerged as an important tool for precision measurement. In this paper, we first study the influences of installation errors for the D-shaped mirror on the displacement measurement. The calibration factor and sensitivity of the different installation parameters are quantified. The results show that the variation of the calibration factor obeys the cosine curve with the angle error, and the sensitivity increases exponentially with the translation error. Besides, we find that the translation error will also lead to crosstalk between transverse and axial displacement. Our work will contribute to improving the performance of optical tweezers for the application in precision measurement and basic physics.
Collapse
|
5
|
Yeng MSM, Ayop SK, Sasaki K. Optical Manipulation of a Liquid Crystal (LC) Microdroplet by Optical Force. CRYSTAL RESEARCH AND TECHNOLOGY 2022. [DOI: 10.1002/crat.202200080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Muhamad Safuan Mat Yeng
- Department of Physics, Faculty of Science and Mathematics Sultan Idris Education University Tanjong Malim Perak 35900 Malaysia
| | - Shahrul Kadri Ayop
- Department of Physics, Faculty of Science and Mathematics Sultan Idris Education University Tanjong Malim Perak 35900 Malaysia
| | - Keiji Sasaki
- Research Institute for Electronic Science Hokkaido University Sapporo 0010020 Japan
| |
Collapse
|
6
|
Geonzon LC, Kobayashi M, Adachi Y. Effect of shear flow on the hydrodynamic drag force of a spherical particle near a wall evaluated using optical tweezers and microfluidics. SOFT MATTER 2021; 17:7914-7920. [PMID: 34373877 DOI: 10.1039/d1sm00876e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The hydrodynamic drag force on a spherical particle in shear flow near-wall is investigated using optical tweezers and microfluidics. Simple shear flow is applied using a microfluidic channel at different volumetric flow rates. The hydrodynamic drag force exerted on the particle is detected from the displacement of the trapped particle. The effect of the wall is obtained from the force balance of the trapping and hydrodynamic drag force employing the exact solution of the theoretical model using the lubrication theory for a sphere near the wall. Here, we report the experimentally obtained hydrodynamic drag force coefficient under the influence of shear flow. The drag correction factor increases with decreasing distance from the wall due to the effect of the wall surface. We found that the calculated hydrodynamic drag force coefficient is in quantitative comparison with the theoretical prediction for a shear flow past a sphere near-wall. This study provides a straightforward investigation of the effect of the shear flow on the hydrodynamic drag force coefficient on a particle near the wall. Furthermore, these pieces of information can be used in various applications, particularly in optimizing microfluidic designs for mixing and separations of particles or exploiting the formation of the concentration gradient of particles perpendicular to flow directions caused by the non-linear hydrodynamic interactions.
Collapse
Affiliation(s)
- Lester C Geonzon
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | | | | |
Collapse
|
7
|
Optimization of Optical Trapping and Laser Interferometry in Biological Cells. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10144970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Optical trapping and laser interferometry enable the non-invasive manipulation of colloids, which can be used to investigate the microscopic mechanics of surrounding media or bound macromolecules. For efficient trapping and precise tracking, the sample media must ideally be homogeneous and quiescent whereas such conditions are usually not satisfied in vivo in living cells. In order to investigate mechanics of the living-cell interior, we introduced (1) the in-situ calibration of optical trapping and laser interferometry, and (2) 3-D feedback control of a sample stage to stably track a colloidal particle. Investigating systematic errors that appear owing to sample heterogeneity and focal offsets of a trapping laser relative to the colloidal probe, we provide several important caveats for conducting precise optical micromanipulation in living cells. On the basis of this study, we further improved the performance of the techniques to be used in cells, by optimizing the position sensitivity of laser interferometry and the stability of the feedback simultaneously.
Collapse
|
8
|
Optical Assembling of Micro-Particles at a Glass–Water Interface with Diffraction Patterns Caused by the Limited Aperture of Objective. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Optical tweezers can manipulate micro-particles, which have been widely used in various applications. Here, we experimentally demonstrate that optical tweezers can assemble the micro-particles to form stable structures at the glass–solution interface in this paper. Firstly, the particles are driven by the optical forces originated from the diffraction fringes, which of the trapping beam passing through an objective with limited aperture. The particles form stable ring structures when the trapping beam is a linearly polarized beam. The particle distributions in the transverse plane are affected by the particle size and concentration. Secondly, the particles form an incompact structure as two fan-shaped after the azimuthally polarized beam passing through a linear polarizer. Furthermore, the particles form a compact structure when a radially polarized beam is used for trapping. Thirdly, the particle patterns can be printed steady at the glass surface in the salt solution. At last, the disadvantage of diffraction traps is discussed in application of optical tweezers. The aggregation of particles at the interfaces seriously affects the flowing of particles in microfluidic channels, and a total reflector as the bottom surface of sample cell can avoid the optical tweezers induced particle patterns at the interface. The optical trapping study utilizing the diffraction gives an interesting method for binding and assembling microparticles, which is helpful to understand the principle of optical tweezers.
Collapse
|
9
|
Yale P, Konin JME, Kouacou MA, Zoueu JT. New Detector Sensitivity Calibration and the Calculation of the Interaction Force between Particles Using an Optical Tweezer. MICROMACHINES 2018; 9:mi9090425. [PMID: 30424358 PMCID: PMC6187551 DOI: 10.3390/mi9090425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 11/16/2022]
Abstract
We propose a new approach to calculate the sensitivity factor of the detector in optical tweezers. In this work, we used a charge-coupled device (CCD) camera and a quadrant photodiode (QPD) for the extraction of the various positions occupied by the trapped object (in this case, silica beads of different diameters). Image-J software and the Boltzmann statistical method were then used to estimate the sensitivity of the detector. Silica beads of diameter 0.8 µm, 2 µm, a system of 2 µm bead stuck to 4.5 µm one and another system of 2 µm beads stuck to 2 µm one, were studied. This work contributes significantly to making better calibration of the detector without taking into account the geometry of the object imprisoned in the optical trap. We further developed an approach to calculate the interaction force between two microbeads. This approach does not require any knowledge of solvent viscosity and works for all types of samples.
Collapse
Affiliation(s)
- Pavel Yale
- Laboratoire d'Instrumentation, Image et Spectroscopie (L2IS), Institut National Polytechnique Houphouët-Boigny (INPHB), BP 1093 Yamoussoukro, Cote D'Ivoire.
| | - Jean-Michel Edoukoua Konin
- Laboratoire d'Instrumentation, Image et Spectroscopie (L2IS), Institut National Polytechnique Houphouët-Boigny (INPHB), BP 1093 Yamoussoukro, Cote D'Ivoire.
| | - Michel Abaka Kouacou
- Laboratoire d'Instrumentation, Image et Spectroscopie (L2IS), Institut National Polytechnique Houphouët-Boigny (INPHB), BP 1093 Yamoussoukro, Cote D'Ivoire.
| | - Jérémie Thouakesseh Zoueu
- Laboratoire d'Instrumentation, Image et Spectroscopie (L2IS), Institut National Polytechnique Houphouët-Boigny (INPHB), BP 1093 Yamoussoukro, Cote D'Ivoire.
| |
Collapse
|
10
|
Porter MD, Giera B, Panas RM, Shaw LA, Shusteff M, Hopkins JB. Experimental characterization and modeling of optical tweezer particle handling dynamics. APPLIED OPTICS 2018; 57:6565-6571. [PMID: 30117897 DOI: 10.1364/ao.57.006565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
We report a new framework for a quantitative understanding of optical trapping (OT) particle handling dynamics. We present a novel three-dimensional particle-based model that includes optical, hydrodynamic, and inter-particle forces. This semi-empirical colloid model is based on an open-source simulation code known as LAMMPS (large-scale atomic/molecular massively parallel simulator) and properly recapitulates the full OT force profile beyond the typical linear approximations valid near the trap center. Simulations are carried out with typical system parameters relevant for our experimental holographic optical trapping (HOT) system, including varied particle sizes, trap movement speeds, and beam powers. Furthermore, we present a new experimental method for measuring both the stable and metastable boundaries of the optical force profile to inform or validate the model's underlying force profile. We show that our framework is a powerful tool for accurately predicting particle behavior in a practical experimental OT setup and can be used to characterize and predict particle handling dynamics within any arbitrary OT force profile.
Collapse
|
11
|
LIANG YANSHENG, CAI YANAN, WANG ZHAOJUN, LEI MING, CAO ZHILIANG, WANG YUE, LI MANMAN, YAN SHAOHUI, BIANCO PIEROR, YAO BAOLI. Aberration correction in holographic optical tweezers using a high-order optical vortex. APPLIED OPTICS 2018; 57:3618-3623. [PMID: 29726541 PMCID: PMC6430200 DOI: 10.1364/ao.57.003618] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Holographic optical tweezers are a powerful optical trapping and manipulation tool in numerous applications such as life science and colloidal physics. However, imperfections in the spatial light modulator and optical components of the system will introduce detrimental aberrations to the system, thereby degrading the trapping performance significantly. To address this issue, we develop an aberration correction technique by using a high-order vortex as the correction metric. The optimal Zernike polynomial coefficients for quantifying the system aberrations are determined by comparing the distorted vortex and the ideal one. Efficiency of the proposed method is demonstrated by comparing the optical trap intensity distribution, trap stiffness, and particle dynamics in a Gaussian trap and an optical vortex trap, before and after aberration corrections.
Collapse
Affiliation(s)
- YANSHENG LIANG
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - YANAN CAI
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - ZHAOJUN WANG
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - MING LEI
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
| | - ZHILIANG CAO
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - YUE WANG
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - MANMAN LI
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - SHAOHUI YAN
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
| | - PIERO R. BIANCO
- Department of Microbiology and Immunology, Department of Biochemistry, Center for Single Molecule Biophysics, 321 Cary Hall, University at Buffalo, Buffalo, New York 14214, USA
| | - BAOLI YAO
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
| |
Collapse
|
12
|
van Mameren J, Wuite GJL, Heller I. Introduction to Optical Tweezers: Background, System Designs, and Commercial Solutions. Methods Mol Biol 2018; 1665:3-23. [PMID: 28940061 DOI: 10.1007/978-1-4939-7271-5_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Optical tweezers are a means to manipulate objects with light. With the technique, microscopically small objects can be held and steered, while forces on the trapped objects can be accurately measured and exerted. Optical tweezers can typically obtain a nanometer spatial resolution, a picoNewton force resolution, and a millisecond time resolution, which makes them excellently suited to study biological processes from the single-cell down to the single-molecule level. In this chapter, we will provide an introduction on the use of optical tweezers in single-molecule approaches. We will introduce the basic principles and methodology involved in optical trapping, force calibration, and force measurements. Next we describe the components of an optical tweezers setup and their experimental relevance in single-molecule approaches. Finally, we provide a concise overview of commercial optical tweezers systems. Commercial systems are becoming increasingly available and provide access to single-molecule optical tweezers experiments without the need for a thorough background in physics.
Collapse
Affiliation(s)
- Joost van Mameren
- Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Gijs J L Wuite
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| | - Iddo Heller
- LaserLaB and Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| |
Collapse
|
13
|
Nishizawa K, Bremerich M, Ayade H, Schmidt CF, Ariga T, Mizuno D. Feedback-tracking microrheology in living cells. SCIENCE ADVANCES 2017; 3:e1700318. [PMID: 28975148 PMCID: PMC5621978 DOI: 10.1126/sciadv.1700318] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/07/2017] [Indexed: 05/12/2023]
Abstract
Living cells are composed of active materials, in which forces are generated by the energy derived from metabolism. Forces and structures self-organize to shape the cell and drive its dynamic functions. Understanding the out-of-equilibrium mechanics is challenging because constituent materials, the cytoskeleton and the cytosol, are extraordinarily heterogeneous, and their physical properties are strongly affected by the internally generated forces. We have analyzed dynamics inside two types of eukaryotic cells, fibroblasts and epithelial-like HeLa cells, with simultaneous active and passive microrheology using laser interferometry and optical trapping technology. We developed a method to track microscopic probes stably in cells in the presence of vigorous cytoplasmic fluctuations, by using smooth three-dimensional (3D) feedback of a piezo-actuated sample stage. To interpret the data, we present a theory that adapts the fluctuation-dissipation theorem (FDT) to out-of-equilibrium systems that are subjected to positional feedback, which introduces an additional nonequilibrium effect. We discuss the interplay between material properties and nonthermal force fluctuations in the living cells that we quantify through the violations of the FDT. In adherent fibroblasts, we observed a well-known polymer network viscoelastic response where the complex shear modulus scales as G* ∝ (-iω)3/4. In the more 3D confluent epithelial cells, we found glassy mechanics with G* ∝ (-iω)1/2 that we attribute to glassy dynamics in the cytosol. The glassy state in living cells shows characteristics that appear distinct from classical glasses and unique to nonequilibrium materials that are activated by molecular motors.
Collapse
Affiliation(s)
- Kenji Nishizawa
- Department of Physics, Graduate School of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Marcel Bremerich
- Department of Physics, Graduate School of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Heev Ayade
- Department of Physics, Graduate School of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Christoph F. Schmidt
- Third Institute of Physics, Faculty of Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Takayuki Ariga
- Department of Physics, Graduate School of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Daisuke Mizuno
- Department of Physics, Graduate School of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| |
Collapse
|
14
|
Zhong MC, Wang ZQ, Li YM. Aberration compensation for optical trapping of cells within living mice. APPLIED OPTICS 2017; 56:1972-1976. [PMID: 28248397 DOI: 10.1364/ao.56.001972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Optical tweezers have been used to trap and manipulate microparticles within living animals. When the optical trap is constructed with an oil-immersion objective, it suffers from spherical aberration. There have been many investigations on the influence of spherical aberration when the particles are trapped in a water medium. However, the dependence of optical force on trapping depth is still ambiguous when the trapped particles are immersed in a high refractive index medium (such as biological tissue, refractive index solution) in experiments. In this paper, the microparticles are immersed in an aqueous solution of glycerol to mimic the cells within biological tissue. As the trapping laser is focused into the specimen, spherical aberration is introduced, degrading the optical trapping performance. It is similar to trapping in water; altering the effective tube length can also compensate for the spherical aberration of the optical trap in a high refractive index medium. Finally, the cells in living mice are trapped by the optical tweezers with the help of spherical aberration compensation.
Collapse
|
15
|
Temperature-driven volume phase transition of a single stimuli-responsive microgel particle using optical tweezers. Colloid Polym Sci 2016. [DOI: 10.1007/s00396-016-3952-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
16
|
Lamprecht A, Lakämper S, Baasch T, Schaap IAT, Dual J. Imaging the position-dependent 3D force on microbeads subjected to acoustic radiation forces and streaming. LAB ON A CHIP 2016; 16:2682-93. [PMID: 27302661 DOI: 10.1039/c6lc00546b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Acoustic particle manipulation in microfluidic channels is becoming a powerful tool in microfluidics to control micrometer sized objects in medical, chemical and biological applications. By creating a standing acoustic wave in the channel, the resulting pressure field can be employed to trap or sort particles. To design efficient and reproducible devices, it is important to characterize the pressure field throughout the volume of the microfluidic device. Here, we used an optically trapped particle as probe to measure the forces in all three dimensions. By moving the probe through the volume of the channel, we imaged spatial variations in the pressure field. In the direction of the standing wave this revealed a periodic energy landscape for 2 μm beads, resulting in an effective stiffness of 2.6 nN m(-1) for the acoustic trap. We found that multiple fabricated devices showed consistent pressure fields. Surprisingly, forces perpendicular to the direction of the standing wave reached values of up to 20% of the main-axis-values. To separate the direct acoustic force from secondary effects, we performed experiments with different bead sizes, which attributed some of the perpendicular forces to acoustic streaming. This method to image acoustically generated forces in 3D can be used to either minimize perpendicular forces or to employ them for specific applications in novel acoustofluidic designs.
Collapse
Affiliation(s)
- Andreas Lamprecht
- Institute for Mechanical Systems, ETH Zurich, 8092 Zurich, Switzerland.
| | - Stefan Lakämper
- Institute for Mechanical Systems, ETH Zurich, 8092 Zurich, Switzerland.
| | - Thierry Baasch
- Institute for Mechanical Systems, ETH Zurich, 8092 Zurich, Switzerland.
| | - Iwan A T Schaap
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Jurg Dual
- Institute for Mechanical Systems, ETH Zurich, 8092 Zurich, Switzerland.
| |
Collapse
|
17
|
Yehoshua S, Pollari R, Milstein JN. Axial Optical Traps: A New Direction for Optical Tweezers. Biophys J 2016; 108:2759-66. [PMID: 26083913 DOI: 10.1016/j.bpj.2015.05.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 03/24/2015] [Accepted: 05/13/2015] [Indexed: 10/23/2022] Open
Abstract
Optical tweezers have revolutionized our understanding of the microscopic world. Axial optical tweezers, which apply force to a surface-tethered molecule by directly moving either the trap or the stage along the laser beam axis, offer several potential benefits when studying a range of novel biophysical phenomena. This geometry, although it is conceptually straightforward, suffers from aberrations that result in variation of the trap stiffness when the distance between the microscope coverslip and the trap focus is being changed. Many standard techniques, such as back-focal-plane interferometry, are difficult to employ in this geometry due to back-scattered light between the bead and the coverslip, whereas the noise inherent in a surface-tethered assay can severely limit the resolution of an experiment. Because of these complications, precision force spectroscopy measurements have adapted alternative geometries such as the highly successful dumbbell traps. In recent years, however, most of the difficulties inherent in constructing a precision axial optical tweezers have been solved. This review article aims to inform the reader about recent progress in axial optical trapping, as well as the potential for these devices to perform innovative biophysical measurements.
Collapse
Affiliation(s)
- Samuel Yehoshua
- Department of Physics, University of Toronto, Toronto, Ontario, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Russell Pollari
- Department of Physics, University of Toronto, Toronto, Ontario, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Joshua N Milstein
- Department of Physics, University of Toronto, Toronto, Ontario, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
18
|
Pollari R, Milstein JN. Improved axial trapping with holographic optical tweezers. OPTICS EXPRESS 2015; 23:28857-28867. [PMID: 26561154 DOI: 10.1364/oe.23.028857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Conventional optical tweezers suffer from several complications when applying axial forces to surface-tethered molecules. Aberrations from the refractive-index mismatch between an oil-immersion objective's medium and the aqueous trapping environment both shift the trap centre and degrade the trapping strength with focal depth. Furthermore, interference effects from back-scattered light make it difficult to use back-focal-plane interferometry for high-bandwidth position detection. Holographic optical tweezers were employed to correct for aberrations to achieve a constant axial stiffness and modulate artifacts from backscattered light. Once the aberrations are corrected for, the trap height can be precisely determined from either the back-scattered light or Brenner's formula.
Collapse
|
19
|
Yuan Y, Li D, Zhang J, Chen X, Zhang C, Ding Z, Wang L, Zhang X, Yuan J, Li Y, Kang Y, Liang G. Bridging cells of three colors with two bio-orthogonal click reactions. Chem Sci 2015; 6:6425-6431. [PMID: 28757958 PMCID: PMC5507188 DOI: 10.1039/c5sc01315a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/25/2015] [Indexed: 01/14/2023] Open
Abstract
Cell-cell interactions play a crucial role in the development and function of multicellular organisms. To study cell-cell interactions in vitro, it is a big challenge for researchers to artificially build up cell junctions to bridge different types of cells for this purpose. Herein, by employing two orthogonal click reactions, we rationally designed four click reagents Mal-CBT, Mal-Cys, Mal-Alkyne, and Mal-N3 and successfully applied them to bridge cells of three colors. Orthogonality between these two click reactions was validated in solution and characterized with HPLC and ESI-MS analyses. After modifications of fluorescent protein-expressing prokaryotic Escherichia coli (E. coli) cells (or eukaryotic HEK 293T cells) of three colors with the reagents Mal-Cys, Mal-CBT and Mal-Alkyne, or Mal-N3 , the cells were sequentially bridged. The HEK 293T cells showed a higher efficiency of cell bridging than the E. coli cells. Finally, using optical tweezers, we quantitatively measured the bridging probability between Mal-Cys-modified and Mal-CBT-modified HEK 293 cells, as well as the rupture force between two bridged cells. We found that the CBT-Cys click reaction markedly improved the efficiency of cell bridging and the rupture force between two bridged cells was measured to be 153.8 pN at a force-loading rate of 49 pN s-1. Our results demonstrate that it is possible to use two (or n) orthogonal click reactions to bridge three (or n + 1) types of cells. Taking the biological importance of cell junctions into consideration, we anticipate that our method of bridging three types of cells with two bio-orthogonal click reactions will be a useful tool for biologists to study cell-cell interactions with more convenience and efficiency.
Collapse
Affiliation(s)
- Yue Yuan
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Di Li
- Hefei National Laboratory for Physical Sciences at the Microscale , Department of Optics and Optical Engineering , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Jia Zhang
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Xianmin Chen
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Chi Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale , Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Zhanling Ding
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Lin Wang
- School of Life Sciences , University of Science and Technology of China , Hefei , Anhui 230027 , China
| | - Xueqian Zhang
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Junhua Yuan
- Hefei National Laboratory for Physical Sciences at the Microscale , Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Yinmei Li
- Hefei National Laboratory for Physical Sciences at the Microscale , Department of Optics and Optical Engineering , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Yanbiao Kang
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| | - Gaolin Liang
- CAS Key Laboratory of Soft Matter Chemistry , Department of Chemistry , University of Science and Technology of China , Hefei , Anhui 230026 , China .
| |
Collapse
|
20
|
Lakämper S, Lamprecht A, Schaap IAT, Dual J. Direct 2D measurement of time-averaged forces and pressure amplitudes in acoustophoretic devices using optical trapping. LAB ON A CHIP 2015; 15:290-300. [PMID: 25370872 DOI: 10.1039/c4lc01144a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Ultrasonic standing waves are increasingly applied in the manipulation and sorting of micrometer-sized particles in microfluidic cells. To optimize the performance of such devices, it is essential to know the exact forces that the particles experience in the acoustic wave. Although much progress has been made via analytical and numerical modeling, the reliability of these methods relies strongly on the assumptions used, e.g. the boundary conditions. Here, we have combined an acoustic flow cell with an optical laser trap to directly measure the force on a single spherical particle in two dimensions. While performing ultrasonic frequency scans, we measured the time-averaged forces on single particles that were moved with the laser trap through the microfluidic cell. The cell including piezoelectric transducers was modeled with finite element methods. We found that the experimentally obtained forces and the derived pressure fields confirm the predictions from theory and modeling. This novel approach can now be readily expanded to other particle, chamber, and fluid regimes and opens up the possibility of studying the effects of the presence of boundaries, acoustic streaming, and non-linear fluids.
Collapse
Affiliation(s)
- Stefan Lakämper
- Department of Mechanical and Process Engineering, Institute of Mechanical Systems, ETH, Zürich, Switzerland.
| | | | | | | |
Collapse
|
21
|
Spyratou E, Cunaj E, Tsigaridas G, Mourelatou EA, Demetzos C, Serafetinides AA, Makropoulou M. Measurements of liposome biomechanical properties by combining line optical tweezers and dielectrophoresis. J Liposome Res 2014; 25:202-210. [DOI: 10.3109/08982104.2014.987784] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
22
|
Wang ZQ, Zhou JH, Zhong MC, Li D, Li YM. Calibration of optical tweezers based on an autoregressive model. OPTICS EXPRESS 2014; 22:16956-16964. [PMID: 25090511 DOI: 10.1364/oe.22.016956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The power spectrum density (PSD) has long been explored for calibrating optical tweezers stiffness. Fast Fourier Transform (FFT) based spectral estimator is typically used. This approach requires a relatively longer data acquisition time to achieve adequate spectral resolution. In this paper, an autoregressive (AR) model is proposed to obtain the Spectrum Density using a limited number of samples. According to our method, the arithmetic model has been established with burg arithmetic, and the final prediction error criterion has been used to select the most appropriate order of the AR model, the power spectrum density has been estimated based the AR model. Then, the optical tweezers stiffness has been determined with the simple calculation from the power spectrum. Since only a small number of samples are used, the data acquisition time is significantly reduced and real-time stiffness calibration becomes feasible. To test this calibration method, we study the variation of the trap stiffness as a function of the parameters of the data length and the trapping depth. Both of the simulation and experiment results have showed that the presented method returns precise results and outperforms the conventional FFT method when using a limited number of samples.
Collapse
|
23
|
|
24
|
Xia P, Zhou J, Song X, Wu B, Liu X, Li D, Zhang S, Wang Z, Yu H, Ward T, Zhang J, Li Y, Wang X, Chen Y, Guo Z, Yao X. Aurora A orchestrates entosis by regulating a dynamic MCAK-TIP150 interaction. J Mol Cell Biol 2014; 6:240-54. [PMID: 24847103 DOI: 10.1093/jmcb/mju016] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Entosis, a cell-in-cell process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TIP150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates microtubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory circuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-molecular association, which perturbs the MCAK-TIP150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 interaction regulates microtubule plasticity to affect the mechanical properties of cells during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 cells. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TIP150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during cell-in-cell processes.
Collapse
Affiliation(s)
- Peng Xia
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Jinhua Zhou
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Xiaoyu Song
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Bing Wu
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Xing Liu
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China Molecular Imaging Center, Atlanta Clinical and Translational Science Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Di Li
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Shuyuan Zhang
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Zhikai Wang
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China Molecular Imaging Center, Atlanta Clinical and Translational Science Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Huijuan Yu
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | - Tarsha Ward
- Molecular Imaging Center, Atlanta Clinical and Translational Science Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA Harvard Medical School, Boston, MA 02115, USA
| | - Jiancun Zhang
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China Guangzhou Institutes of Biomedicine and Health, Guangzhou 510513, China
| | - Yinmei Li
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| | | | - Yong Chen
- Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Zhen Guo
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China Molecular Imaging Center, Atlanta Clinical and Translational Science Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Xuebiao Yao
- Anhui Key Laboratory of Cellular Dynamics & Chemical Biology, Department of Optics and Optical Engineering, and Hefei National Laboratory for Physical Sciences at Nanoscale, University of Science and Technology of China, Hefei 230027, China
| |
Collapse
|
25
|
Sarshar M, Wong WT, Anvari B. Comparative study of methods to calibrate the stiffness of a single-beam gradient-force optical tweezers over various laser trapping powers. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:115001. [PMID: 25375348 PMCID: PMC4221290 DOI: 10.1117/1.jbo.19.11.115001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 09/16/2014] [Accepted: 09/29/2014] [Indexed: 05/13/2023]
Abstract
Optical tweezers have become an important instrument in force measurements associated with various physical, biological, and biophysical phenomena. Quantitative use of optical tweezers relies on accurate calibration of the stiffness of the optical trap. Using the same optical tweezers platform operating at 1064 nm and beads with two different diameters, we present a comparative study of viscous drag force, equipartition theorem, Boltzmann statistics, and power spectral density (PSD) as methods in calibrating the stiffness of a single beam gradient force optical trap at trapping laser powers in the range of 0.05 to 1.38 W at the focal plane. The equipartition theorem and Boltzmann statistic methods demonstrate a linear stiffness with trapping laser powers up to 355 mW, when used in conjunction with video position sensing means. The PSD of a trapped particle's Brownian motion or measurements of the particle displacement against known viscous drag forces can be reliably used for stiffness calibration of an optical trap over a greater range of trapping laser powers. Viscous drag stiffness calibration method produces results relevant to applications where trapped particle undergoes large displacements, and at a given position sensing resolution, can be used for stiffness calibration at higher trapping laser powers than the PSD method.
Collapse
Affiliation(s)
- Mohammad Sarshar
- University of California, Department of Bioengineering, Riverside, California 92521, United States
| | - Winson T. Wong
- University of California, Department of Bioengineering, Riverside, California 92521, United States
| | - Bahman Anvari
- University of California, Department of Bioengineering, Riverside, California 92521, United States
| |
Collapse
|
26
|
Richly MU, Türkcan S, Le Gall A, Fiszman N, Masson JB, Westbrook N, Perronet K, Alexandrou A. Calibrating optical tweezers with Bayesian inference. OPTICS EXPRESS 2013; 21:31578-31590. [PMID: 24514731 DOI: 10.1364/oe.21.031578] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a new method for calibrating an optical-tweezer setup that does not depend on input parameters and is less affected by systematic errors like drift of the setup. It is based on an inference approach that uses Bayesian probability to infer the diffusion coefficient and the potential felt by a bead trapped in an optical or magnetic trap. It exploits a much larger amount of the information stored in the recorded bead trajectory than standard calibration approaches. We demonstrate that this method outperforms the equipartition method and the power-spectrum method in input information required (bead radius and trajectory length) and in output accuracy.
Collapse
|
27
|
Zhong MC, Gong L, Zhou JH, Wang ZQ, Li YM. Optical trapping of red blood cells in living animals with a water immersion objective. OPTICS LETTERS 2013; 38:5134-5137. [PMID: 24281528 DOI: 10.1364/ol.38.005134] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We demonstrate optical trapping of red blood cells (RBCs) in living animals by using a water immersion objective. First, the cells within biological tissue are mimicked by the particles immersed in aqueous solutions of glycerol. The optical forces depending on trapping depth are investigated when a parallel laser beam enters the water immersion objective. The results show that the optical forces vary with trapping depth, and the optimal trapping depth in aqueous solutions of glycerol (n=1.39) is 50 μm. Second, the optimal trapping depth in aqueous solutions of glycerol can be changed by altering the actual tube length of the water immersion objective. Finally, we achieved optical trapping and manipulation of RBCs in living mice.
Collapse
|
28
|
Bodensiek K, Li W, Sánchez P, Nawaz S, Schaap IAT. A high-speed vertical optical trap for the mechanical testing of living cells at piconewton forces. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:113707. [PMID: 24289404 DOI: 10.1063/1.4832036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Although atomic force microscopy is often the method of choice to probe the mechanical response of (sub)micrometer sized biomaterials, the lowest force that can be reliably controlled is limited to ≈0.1 nN. For soft biological samples, like cells, such forces can already lead to a strain large enough to enter the non-elastic deformation regime. To be able to investigate the response of single cells at lower forces we developed a vertical optical trap. The force can be controlled down to single piconewtons and most of the advantages of atomic force microscopy are maintained, such as the symmetrical application of forces at a wide range of loading rates. Typical consequences of moving the focus in the vertical direction, like the interferometric effect between the bead and the coverslip and a shift of focus, were quantified and found to have negligible effects on our measurements. With a fast responding force feedback loop we can achieve deformation rates as high as 50 μm/s, which allow the investigation of the elastic and viscous components of very soft samples. The potential of the vertical optical trap is demonstrated by measuring the linearity of the response of single cells at very low forces and a high bandwidth of deformation rates.
Collapse
Affiliation(s)
- Kai Bodensiek
- III. Physikalisches Institut, Georg-August-Universität, Göttingen, Germany
| | | | | | | | | |
Collapse
|
29
|
Bernatová S, Samek O, Pilát Z, Šerý M, Ježek J, Jákl P, Šiler M, Krzyžánek V, Zemánek P, Holá V, Dvořáčková M, Růžička F. Following the mechanisms of bacteriostatic versus bactericidal action using Raman spectroscopy. Molecules 2013; 18:13188-99. [PMID: 24284484 PMCID: PMC6270526 DOI: 10.3390/molecules181113188] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/10/2013] [Accepted: 10/17/2013] [Indexed: 11/17/2022] Open
Abstract
Antibiotics cure infections by influencing bacterial growth or viability. Antibiotics can be divided to two groups on the basis of their effect on microbial cells through two main mechanisms, which are either bactericidal or bacteriostatic. Bactericidal antibiotics kill the bacteria and bacteriostatic antibiotics suppress the growth of bacteria (keep them in the stationary phase of growth). One of many factors to predict a favorable clinical outcome of the potential action of antimicrobial chemicals may be provided using in vitro bactericidal/bacteriostatic data (e.g., minimum inhibitory concentrations—MICs). Consequently, MICs are used in clinical situations mainly to confirm resistance, and to determine the in vitro activities of new antimicrobials. We report on the combination of data obtained from MICs with information on microorganisms’ “fingerprint” (e.g., DNA/RNA, and proteins) provided by Raman spectroscopy. Thus, we could follow mechanisms of the bacteriostatic versus bactericidal action simply by detecting the Raman bands corresponding to DNA. The Raman spectra of Staphylococcus epidermidis treated with clindamycin (a bacteriostatic agent) indeed show little effect on DNA which is in contrast with the action of ciprofloxacin (a bactericidal agent), where the Raman spectra show a decrease in strength of the signal assigned to DNA, suggesting DNA fragmentation.
Collapse
Affiliation(s)
- Silvie Bernatová
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Ota Samek
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +420-5-41514-284; Fax: +420-5-41514-402
| | - Zdeněk Pilát
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Mojmír Šerý
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Jan Ježek
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Petr Jákl
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Martin Šiler
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Vladislav Krzyžánek
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Pavel Zemánek
- Institute of Scientific Instruments of the Academy of Science of the Czech republic, v.v.i., Královopolská 147, 612 64 Brno, Czech Republic; E-Mails: (S.B.); (Z.P.); (M.Š.); (J.J.); (P.J.); (M.Š.); (V.K.); (P.Z.)
| | - Veronika Holá
- Department of Microbiology, Faculty of Medicine and St. Anne’s Faculty Hospital, Brno, Czech Republic; E-Mails: (V.H.); (M.D.); (F.R.)
| | - Milada Dvořáčková
- Department of Microbiology, Faculty of Medicine and St. Anne’s Faculty Hospital, Brno, Czech Republic; E-Mails: (V.H.); (M.D.); (F.R.)
| | - Filip Růžička
- Department of Microbiology, Faculty of Medicine and St. Anne’s Faculty Hospital, Brno, Czech Republic; E-Mails: (V.H.); (M.D.); (F.R.)
| |
Collapse
|
30
|
Dear RD, Worrall EK, Gault WD, Ritchie GAD. Microrheological Investigations in Ionic Liquids Using Optical Trapping Techniques. J Phys Chem B 2013; 117:10567-71. [DOI: 10.1021/jp405986q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Richard D. Dear
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Emma K. Worrall
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - William D. Gault
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Grant A. D. Ritchie
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| |
Collapse
|
31
|
Trapping red blood cells in living animals using optical tweezers. Nat Commun 2013; 4:1768. [DOI: 10.1038/ncomms2786] [Citation(s) in RCA: 251] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 03/22/2013] [Indexed: 11/08/2022] Open
|
32
|
Lei M, Li Z, Yan S, Yao B, Dan D, Qi Y, Qian J, Yang Y, Gao P, Ye T. Long-distance axial trapping with focused annular laser beams. PLoS One 2013; 8:e57984. [PMID: 23505449 PMCID: PMC3591451 DOI: 10.1371/journal.pone.0057984] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/29/2013] [Indexed: 11/19/2022] Open
Abstract
Focusing an annular laser beam can improve the axial trapping efficiency due to the reduction of the scattering force, which enables the use of a lower numerical aperture (NA) objective lens with a long working distance to trap particles in deeper aqueous medium. In this paper, we present an axicon-to-axicon scheme for producing parallel annular beams with the advantages of higher efficiency compared with the obstructed beam approach. The validity of the scheme is verified by the observation of a stable trapping of silica microspheres with relatively low NA microscope objective lenses (NA = 0.6 and 0.45), and the axial trapping depth of 5 mm is demonstrated in experiment.
Collapse
Affiliation(s)
- Ming Lei
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Ze Li
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Shaohui Yan
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Baoli Yao
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Dan Dan
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Yujiao Qi
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Jia Qian
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Yanlong Yang
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Peng Gao
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| | - Tong Ye
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China
| |
Collapse
|
33
|
Mack AH, Schlingman DJ, Regan L, Mochrie SGJ. Practical axial optical trapping. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:103106. [PMID: 23126750 PMCID: PMC3482253 DOI: 10.1063/1.4757862] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/19/2012] [Indexed: 06/01/2023]
Abstract
We describe a new method for calibrating optical trapping measurements in which tension is applied in the direction of the laser beam to a molecule tethered between a surface and an optically trapped bead. Specifically, we present a generally-applicable procedure for converting from the measured scattering intensity and the measured stage displacement to applied tension and bead-coverslip separation, using measurements of the light intensity scattered from an untethered, trapped bead. Our calibration accounts for a number of effects, including aberrations and the interference of forward-reflected bead-scattered light with the trapping beam. To demonstrate the accuracy of our method, we show measurements of the DNA force-versus-extension relation using a range of laser intensities, and show that these measurements match the expected extensible wormlike-chain (WLC) behavior. Finally, we also demonstrate a force-clamp, in which the tension in a tether is held fixed while the extension varies as a result of molecular events.
Collapse
Affiliation(s)
- A H Mack
- Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, Connecticut 06511, USA
| | | | | | | |
Collapse
|
34
|
Cell visco-elasticity measured with AFM and optical trapping at sub-micrometer deformations. PLoS One 2012; 7:e45297. [PMID: 23028915 PMCID: PMC3446885 DOI: 10.1371/journal.pone.0045297] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/20/2012] [Indexed: 11/23/2022] Open
Abstract
The measurement of the elastic properties of cells is widely used as an indicator for cellular changes during differentiation, upon drug treatment, or resulting from the interaction with the supporting matrix. Elasticity is routinely quantified by indenting the cell with a probe of an AFM while applying nano-Newton forces. Because the resulting deformations are in the micrometer range, the measurements will be affected by the finite thickness of the cell, viscous effects and even cell damage induced by the experiment itself. Here, we have analyzed the response of single 3T3 fibroblasts that were indented with a micrometer-sized bead attached to an AFM cantilever at forces from 30–600 pN, resulting in indentations ranging from 0.2 to 1.2 micrometer. To investigate the cellular response at lower forces up to 10 pN, we developed an optical trap to indent the cell in vertical direction, normal to the plane of the coverslip. Deformations of up to two hundred nanometers achieved at forces of up to 30 pN showed a reversible, thus truly elastic response that was independent on the rate of deformation. We found that at such small deformations, the elastic modulus of 100 Pa is largely determined by the presence of the actin cortex. At higher indentations, viscous effects led to an increase of the apparent elastic modulus. This viscous contribution that followed a weak power law, increased at larger cell indentations. Both AFM and optical trapping indentation experiments give consistent results for the cell elasticity. Optical trapping has the benefit of a lower force noise, which allows a more accurate determination of the absolute indentation. The combination of both techniques allows the investigation of single cells at small and large indentations and enables the separation of their viscous and elastic components.
Collapse
|
35
|
Nijenhuis N, Mizuno D, Spaan JAE, Schmidt CF. High-resolution microrheology in the pericellular matrix of prostate cancer cells. J R Soc Interface 2012; 9:1733-44. [PMID: 22319113 DOI: 10.1098/rsif.2011.0825] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many cells express a membrane-coupled external mechanical layer, the pericellular matrix (PCM), which often contains long-chain polymers. Its role and properties are not entirely known, but its functions are believed to include physical protection, mechanosensing, chemical signalling or lubrication. The viscoelastic response of the PCM, with polysaccharides as the main structural components, is therefore crucial for the understanding of its function. We have here applied microrheology, based on optically trapped micrometre-sized colloids, to the PCM of cultured PC3 prostate cancer cells. This technology allowed us to measure the extremely soft response of the PCM, with approximately 1 µm height resolution. Exogenously added aggrecan, a hyaluronan-binding proteoglycan, caused a remarkable increase in thickness of the viscoelastic layer and also triggered filopodia-like protrusions. The viscoelastic response of the PCM, however, did not change significantly.
Collapse
Affiliation(s)
- Nadja Nijenhuis
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
36
|
Junio J, Ng J, Cohen JA, Lin Z, Ou-Yang HD. Ensemble method to measure the potential energy of nanoparticles in an optical trap. OPTICS LETTERS 2011; 36:1497-9. [PMID: 21499402 DOI: 10.1364/ol.36.001497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A method is described for measuring the potential energy of nanoparticles in an optical trap by trapping an ensemble of particles with a focused laser beam. The force balance between repulsive osmotic and confining gradient-force pressures determines the single-particle trapping potential independent of interactions between the particles. The ensemble nature of the measurement permits evaluation of single-particle trapping energies much smaller than kBT. Energies obtained by this method are compared to those of single-particle methods as well as to theoretical calculations based on classical electromagnetic optics.
Collapse
Affiliation(s)
- Joseph Junio
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | | | | | | | | |
Collapse
|
37
|
van Mameren J, Wuite GJL, Heller I. Introduction to optical tweezers: background, system designs, and commercial solutions. Methods Mol Biol 2011; 783:1-20. [PMID: 21909880 DOI: 10.1007/978-1-61779-282-3_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Optical tweezers are a means to manipulate objects with light. With the technique, microscopically small objects can be held and steered while forces on the trapped objects can be accurately measured and exerted. Optical tweezers can typically obtain a nanometer spatial resolution, a piconewton force resolution, and a millisecond time resolution, which make them excellently suited to study biological processes from the single-cell down to the single-molecule level. In this chapter, we provide an introduction on the use of optical tweezers in single-molecule approaches. We introduce the basic principles and methodology involved in optical trapping, force calibration, and force measurements. Next, we describe the components of an optical tweezers setup and their experimental relevance in single-molecule approaches. Finally, we provide a concise overview of commercial optical tweezers systems. Commercial systems are becoming increasingly available and provide access to single-molecule optical tweezers experiments without the need for a thorough background in physics.
Collapse
|
38
|
Burnham DR, Reece PJ, McGloin D. Parameter exploration of optically trapped liquid aerosols. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:051123. [PMID: 21230453 DOI: 10.1103/physreve.82.051123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Indexed: 05/30/2023]
Abstract
When studying the motion of optically trapped particles on the microsecond time scale, in low-viscosity media such as air, inertia cannot be neglected. Resolution of unusual and interesting behavior not seen in colloidal trapping experiments is possible. In an attempt to explain the phenomena we use power-spectral methods to perform a parameter study of the Brownian motion of optically trapped liquid aerosol droplets concentrated around the critically damped regime. We present evidence that the system is suitably described by a simple harmonic oscillator model which must include a description of Faxén's correction, but not necessarily frequency dependent hydrodynamic corrections to Stokes' law. We also provide results describing how the system behaves under several variables and discuss the difficulty in decoupling the parameters responsible for the observed behavior. We show that due to the relatively low dynamic viscosity and high trap stiffness, it is easy to transfer between over- and underdamped motion by experimentally altering either trap stiffness or damping. Our results suggest stable aerosol trapping may be achieved in underdamped conditions, but the onset of deleterious optical forces at high trapping powers prevents the probing of the upper stability limits due to Brownian motion.
Collapse
Affiliation(s)
- D R Burnham
- SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife KY16 9SS, United Kingdom
| | | | | |
Collapse
|
39
|
Tauro S, Bañas A, Palima D, Glückstad J. Dynamic axial stabilization of counter-propagating beam-traps with feedback control. OPTICS EXPRESS 2010; 18:18217-18222. [PMID: 20721211 DOI: 10.1364/oe.18.018217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
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 computer-vision object tracking of the axial position, in conjunction with software-based 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.
Collapse
Affiliation(s)
- Sandeep Tauro
- DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | | | | | | |
Collapse
|
40
|
Hong Y, Pyo JW, Baek SH, Lee SW, Yoon DS, No K, Kim BM. Quantitative measurements of absolute dielectrophoretic forces using optical tweezers. OPTICS LETTERS 2010; 35:2493-5. [PMID: 20634874 DOI: 10.1364/ol.35.002493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Optical tweezers were used for quantitative measurement of the absolute dielectrophoresis (DEP) forces acting on polystyrene microparticles. The electrodes and tweezers were configured to create one-dimensional DEP forces acting perpendicular to the tweezers' beam. The influences of various external factors, such as applied voltage frequency, conductivity of the medium, and particle size on the measurement were estimated. By accounting for these factors, actual measurements were in close agreement with theoretical predictions. Our results show that the optical tweezers may serve as a unique tool for the measurement of DEP forces in various applications.
Collapse
Affiliation(s)
- Yoochan Hong
- Department of Biomedical Engineering, Yonsei University, Wonju, Gangwondo 220-710, Korea
| | | | | | | | | | | | | |
Collapse
|
41
|
Gross P, Farge G, Peterman EJG, Wuite GJL. Combining optical tweezers, single-molecule fluorescence microscopy, and microfluidics for studies of DNA-protein interactions. Methods Enzymol 2010; 475:427-53. [PMID: 20627167 DOI: 10.1016/s0076-6879(10)75017-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The technically challenging field of single-molecule biophysics has established itself in the last decade by granting access to detailed information about the fate of individual biomolecules, unattainable in traditional biochemical assays. The appeal of single-molecule methods lies in the directness of the information obtained from individual biomolecules. Technological improvements in single-molecule methods have made it possible to combine optical tweezers, fluorescence microscopy, and microfluidic flow systems. Such a combination of techniques has opened new possibilities to study complex biochemical reactions on the single-molecule level. In this chapter, we provide general considerations for the development of a combined optical trapping, fluorescence microscopy, and microfluidics instrument, along with methods to solve technical issues that are critical for designing successful experiments. Finally, we present several experiments to illustrate the power of this combination of techniques.
Collapse
Affiliation(s)
- Peter Gross
- Department of Physics and Astronomy and Laser Centre, VU University, De Boelelaan, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
42
|
Zhong MC, Zhou JH, Ren YX, Li YM, Wang ZQ. Rotation of birefringent particles in optical tweezers with spherical aberration. APPLIED OPTICS 2009; 48:4397-4402. [PMID: 19649044 DOI: 10.1364/ao.48.004397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Birefringent particles rotate when trapped in elliptically polarized light. When an infinity corrected oil-immersion objective is used for trapping, rotation of birefringent particles in optical tweezers based on an infinity optical microscope is affected by the spherical aberration at the glass-water interface. The maximum rotation rate of birefringent particles occurs close to the coverslip, and the rotation rate decreases dramatically as the trapped depth increases. We experimentally demonstrate that spherical aberration can be compensated by using a finite-distance-corrected objective to trap and rotate the birefringent particles. It is found that the trapped depth corresponding to the maximum rotation rate is 50 microm, and the rotation rates at deep trapped depths are improved.
Collapse
Affiliation(s)
- Min-Cheng Zhong
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | | | | | | | | |
Collapse
|
43
|
Sun B, Lin J, Darby E, Grosberg AY, Grier DG. Brownian vortexes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:010401. [PMID: 19658638 DOI: 10.1103/physreve.80.010401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Indexed: 05/28/2023]
Abstract
Mechanical equilibrium at zero temperature does not necessarily imply thermodynamic equilibrium at finite temperature for a particle confined by a static but nonconservative force field. Instead, the diffusing particle can enter into a steady state characterized by toroidal circulation in the probability flux, which we call a Brownian vortex. The circulatory bias in the particle's thermally driven trajectory is not simply a deterministic response to the solenoidal component of the force but rather reflects interplay between advection and diffusion in which thermal fluctuations extract work from the nonconservative force field. As an example of this previously unrecognized class of stochastic heat engines, we consider a colloidal sphere diffusing in a conventional optical tweezer. We demonstrate both theoretically and experimentally that nonconservative optical forces bias the particle's fluctuations into toroidal vortexes whose circulation can reverse direction with temperature or laser power.
Collapse
Affiliation(s)
- Bo Sun
- Department of Physics and Center for Soft Matter Research, New York University, New York, New York 10003, USA
| | | | | | | | | |
Collapse
|
44
|
Nijenhuis N, Mizuno D, Spaan JAE, Schmidt CF. Viscoelastic response of a model endothelial glycocalyx. Phys Biol 2009; 6:025014. [PMID: 19571362 DOI: 10.1088/1478-3975/6/2/025014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Many cells cover themselves with a multifunctional polymer coat, the pericellular matrix (PCM), to mediate mechanical interactions with the environment. A particular PCM, the endothelial glycocalyx (EG), is formed by vascular endothelial cells at their luminal side, forming a mechanical interface between the flowing blood and the endothelial cell layer. The glycosaminoglycan (GAG) hyaluronan (HA) is involved in the main functions of the EG, mechanotransduction of fluid shear stress and molecular sieving. HA, due to its length, is the only GAG in the EG or any other PCM able to form an entangled network. The mechanical functions of the EG are, however, impaired when any one of its components is removed. We here used microrheology to measure the effect of the EG constituents heparan sulfate, chondroitin sulfate, whole blood plasma and albumin on the high-bandwidth mechanical properties of a HA solution. Furthermore, we probed the effect of the hyaldherin aggrecan, a constituent of the PCM of chondrocytes, and very similar to versican (present in the PCM of various cells, and possibly in the EG). We show that components directly interacting with HA (chondroitin sulfate and aggrecan) can increase the viscoelastic shear modulus of the polymer composite.
Collapse
Affiliation(s)
- Nadja Nijenhuis
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
45
|
|
46
|
Leach J, Mushfique H, Keen S, Di Leonardo R, Ruocco G, Cooper JM, Padgett MJ. Comparison of Faxén's correction for a microsphere translating or rotating near a surface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:026301. [PMID: 19391834 DOI: 10.1103/physreve.79.026301] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Indexed: 05/05/2023]
Abstract
Boundary walls in microfluidic devices have a strong influence on the fluid flow and drag forces on moving objects. The Stokes drag force acting on a sphere translating in the fluid is increased by the presence of a neighboring wall by a factor given by Faxén's correction. A similar increase in the rotational drag is expected when spinning close to a wall. We use optical tweezers to confirm the translational drag correction and report the hitherto unmeasured rotational equivalent. We find that the corrections for the rotational motion is only required for particle-wall separations an order of magnitude shorter than that for the translational cases. These results are particularly significant in the use of optical tweezers for measuring viscosity on a picolitre scale.
Collapse
Affiliation(s)
- J Leach
- Department of Physics and Astronomy, University of Glasgow, Glasgow, Scotland.
| | | | | | | | | | | | | |
Collapse
|
47
|
Mizuno D, Head DA, MacKintosh FC, Schmidt CF. Active and Passive Microrheology in Equilibrium and Nonequilibrium Systems. Macromolecules 2008. [DOI: 10.1021/ma801218z] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D. Mizuno
- Organization for the Promotion of Advanced Research, Kyushu University, 812-0054 Fukuoka, Japan; Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan; Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, The Netherlands; and III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, 37077 Göttingen, Germany
| | - D. A. Head
- Organization for the Promotion of Advanced Research, Kyushu University, 812-0054 Fukuoka, Japan; Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan; Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, The Netherlands; and III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, 37077 Göttingen, Germany
| | - F. C. MacKintosh
- Organization for the Promotion of Advanced Research, Kyushu University, 812-0054 Fukuoka, Japan; Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan; Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, The Netherlands; and III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, 37077 Göttingen, Germany
| | - C. F. Schmidt
- Organization for the Promotion of Advanced Research, Kyushu University, 812-0054 Fukuoka, Japan; Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan; Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, The Netherlands; and III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, 37077 Göttingen, Germany
| |
Collapse
|
48
|
Roichman Y, Sun B, Stolarski A, Grier DG. Influence of nonconservative optical forces on the dynamics of optically trapped colloidal spheres: the fountain of probability. PHYSICAL REVIEW LETTERS 2008; 101:128301. [PMID: 18851418 DOI: 10.1103/physrevlett.101.128301] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 04/04/2008] [Indexed: 05/26/2023]
Abstract
We demonstrate both experimentally and theoretically that a colloidal sphere trapped in a static optical tweezer does not come to equilibrium, but rather reaches a steady state in which its probability flux traces out a toroidal vortex. This nonequilibrium behavior can be ascribed to a subtle bias of thermal fluctuations by nonconservative optical forces. The circulating sphere therefore acts as a Brownian motor. We briefly discuss ramifications of this effect for studies in which optical tweezers have been treated as potential energy wells.
Collapse
Affiliation(s)
- Yohai Roichman
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA
| | | | | | | |
Collapse
|
49
|
Nijenhuis N, Mizuno D, Schmidt CF, Vink H, Spaan JAE. Microrheology of Hyaluronan Solutions: Implications for the Endothelial Glycocalyx. Biomacromolecules 2008; 9:2390-8. [DOI: 10.1021/bm800381z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nadja Nijenhuis
- Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan, III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, Göttingen, Germany, and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Daisuke Mizuno
- Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan, III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, Göttingen, Germany, and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Christoph F. Schmidt
- Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan, III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, Göttingen, Germany, and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Hans Vink
- Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan, III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, Göttingen, Germany, and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Jos A. E. Spaan
- Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, Organization for the Promotion of Advanced Research, Kyushu University, Fukuoka, Japan, III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, Göttingen, Germany, and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
50
|
van Mameren J, Peterman EJG, Wuite GJL. See me, feel me: methods to concurrently visualize and manipulate single DNA molecules and associated proteins. Nucleic Acids Res 2008; 36:4381-9. [PMID: 18586820 PMCID: PMC2490750 DOI: 10.1093/nar/gkn412] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Direct visualization of DNA and proteins allows researchers to investigate DNA–protein interactions with great detail. Much progress has been made in this area as a result of increasingly sensitive single-molecule fluorescence techniques. At the same time, methods that control the conformation of DNA molecules have been improving constantly. The combination of both techniques has appealed to researchers ever since single-molecule measurements have become possible and indeed first implementations of such combined approaches have proven useful in the study of several DNA-binding proteins in real time. Here, we describe the technical state-of-the-art of various integrated manipulation-and-visualization methods. We first discuss methods that allow only little control over the DNA conformation, such as DNA combing. We then describe DNA flow-stretching approaches that allow more control, and end with the full control on position and extension obtained by manipulating DNA with optical tweezers. The advantages and limitations of the various techniques are discussed, as well as several examples of applications to biophysical or biochemical questions. We conclude with an outlook describing potential future technical developments in combining fluorescence microscopy with DNA micromanipulation technology.
Collapse
Affiliation(s)
- Joost van Mameren
- Department of Physics and Astronomy and Laser Centre, VU University, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | | | | |
Collapse
|