Construction and calibration of an optical trap on a fluorescence optical microscope

The application of optical traps has come to the fore in the last three decades. They provide a powerful, sterile and noninvasive tool for the manipulation of cells, single biological macromolecules, colloidal microparticles and nanoparticles. An optically trapped microsphere may act as a force transducer that is used to measure forces in the piconewton regime. By setting up a well-calibrated single-beam optical trap within a fluorescence microscope system, one can measure forces and collect fluorescence signals upon biological systems simultaneously. In this protocol, we aim to provide a clear exposition of the methodology of assembling and operating a single-beam gradient force trap (optical tweezers) on an inverted fluorescence microscope. A step-by-step guide is given for alignment and operation, with discussion of common pitfalls.

[1]  Christoph F. Schmidt,et al.  Direct observation of kinesin stepping by optical trapping interferometry , 1993, Nature.

[2]  K. Svoboda,et al.  Biological applications of optical forces. , 1994, Annual review of biophysics and biomolecular structure.

[3]  K. Neuman,et al.  Optical trapping. , 2004, The Review of scientific instruments.

[4]  Polly M Fordyce,et al.  Simultaneous, coincident optical trapping and single-molecule fluorescence , 2004, Nature Methods.

[5]  S. Block,et al.  Construction of multiple-beam optical traps with nanometer-resolution position sensing , 1996 .

[6]  C. Schmidt,et al.  Interference model for back-focal-plane displacement detection in optical tweezers. , 1998, Optics letters.

[7]  W. Brownell,et al.  Membrane tether formation from outer hair cells with optical tweezers. , 2002, Biophysical journal.

[8]  Kishan Dholakia,et al.  Beth's experiment using optical tweezers , 2001 .

[9]  V. Subramaniam,et al.  Force detection in optical tweezers using backscattered light. , 2005, Optics express.

[10]  O. Axner,et al.  Design for fully steerable dual-trap optical tweezers. , 1997, Applied optics.

[11]  Steven M Block,et al.  Resource Letter: LBOT-1: Laser-based optical tweezers. , 2003, American journal of physics.

[12]  Yael Roichman,et al.  Optimized holographic optical traps. , 2005, Optics express.

[13]  S. Chu,et al.  Observation of a single-beam gradient force optical trap for dielectric particles. , 1986, Optics letters.

[14]  Steven M Block,et al.  Passive all-optical force clamp for high-resolution laser trapping. , 2005, Physical review letters.

[15]  E. Stelzer,et al.  Trapping and tracking a local probe with a photonic force microscope , 2004 .

[16]  Steven M. Block,et al.  Optical trapping of metallic Rayleigh particles. , 1994, Optics letters.

[17]  Ignacio Tinoco,et al.  Temperature control methods in a laser tweezers system. , 2005, Biophysical journal.

[18]  Kishan Dholakia,et al.  Optical micromanipulation takes hold , 2006, SPIE Optics + Photonics.

[19]  H. Flyvbjerg,et al.  Power spectrum analysis for optical tweezers , 2004 .

[20]  K Bergman,et al.  Characterization of photodamage to Escherichia coli in optical traps. , 1999, Biophysical journal.

[21]  Arthur Ashkin,et al.  Optical Trapping and Manipulation of Neutral Particles Using Lasers , 1999 .

[22]  H. Flyvbjerg,et al.  MatLab program for precision calibration of optical tweezers , 2004 .

[23]  Miles J. Padgett,et al.  Axial and lateral trapping efficiency of Laguerre–Gaussian modes in inverted optical tweezers , 2001 .

[24]  P. Zemánek,et al.  Single-beam trapping in front of reflective surfaces. , 2001, Optics letters.

[25]  Hyungsuk Lee,et al.  Optical trapping for undergraduates , 2007 .

[26]  C. Bustamante,et al.  Ten years of tension: single-molecule DNA mechanics , 2003, Nature.

[27]  John Bechhoefer,et al.  Faster, cheaper, safer optical tweezers for the undergraduate laboratory , 2002 .

[28]  Stephen R Quake,et al.  Behavior of complex knots in single DNA molecules. , 2003, Physical review letters.

[29]  Mara Prentiss,et al.  Inexpensive optical tweezers for undergraduate laboratories , 1999 .

[30]  Paul Matsudaira,et al.  Detecting force-induced molecular transitions with fluorescence resonant energy transfer. , 2007, Angewandte Chemie.

[31]  J. Spudich,et al.  Single myosin molecule mechanics: piconewton forces and nanometre steps , 1994, Nature.

[32]  S. Smith,et al.  Single-molecule studies of DNA mechanics. , 2000, Current opinion in structural biology.