title: Construction and calibration of an optical trap on a fluorescence optical microscope.
abstract: 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.
authors: SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK.
authors: Woei Ming
authors: WM
authors: Lee
authors: Peter J
authors: PJ
authors: Reece
authors: Robert F
authors: RF
authors: Marchington
authors: Nikolaus K
authors: NK
authors: Metzger
authors: Kishan
authors: K
authors: Dholakia
mesh_terms: D008846:Micromanipulation / Q000295:instrumentation; D008856:Microscopy, Fluorescence / Q000295:instrumentation*; D008863:Microspheres; D052898:Optical Tweezers; D055095:Optics and Photonics / Q000295:instrumentation; D010316:Particle Size