title: Motion analysis of optically trapped particles and cells using 2D Fourier analysis.
abstract: Motion analysis of optically trapped objects is demonstrated using a simple 2D Fourier transform technique. The displacements of trapped objects are determined directly from the phase shift between the Fourier transform of subsequent images. Using end- and side-view imaging, the stiffness of the trap is determined in three dimensions. The Fourier transform method is simple to implement and applicable in cases where the trapped object changes shape or where the lighting conditions change. This is illustrated by tracking a fluorescent particle and a myoblast cell, with subsequent determination of diffusion coefficients and the trapping forces.
authors.affiliation: iNANO, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark.
authors.forename: Martin Verner
authors.initials: MV
authors.lastname: Kristensen
authors.forename: Peter
authors.initials: P
authors.lastname: Ahrendt
authors.forename: Thue Bjerring
authors.initials: TB
authors.lastname: Lindballe
authors.forename: Otto Højager Attermann
authors.initials: OH
authors.lastname: Nielsen
authors.forename: Anton P
authors.initials: AP
authors.lastname: Kylling
authors.forename: Henrik
authors.initials: H
authors.lastname: Karstoft
authors.forename: Alberto
authors.initials: A
authors.lastname: Imparato
authors.forename: Leticia
authors.initials: L
authors.lastname: Hosta-Rigau
authors.forename: Brigitte
authors.initials: B
authors.lastname: Stadler
authors.forename: Henrik
authors.initials: H
authors.lastname: Stapelfeldt
authors.forename: Søren Rud
authors.initials: SR
authors.lastname: Keiding
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology / Q000528:radiation effects; D002478:Cells, Cultured; D003198:Computer Simulation; D005583:Fourier Analysis; D051379:Mice; D008954:Models, Biological; D008956:Models, Chemical; D032446:Myoblasts / Q000502:physiology* / Q000528:radiation effects*; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects*; D052898:Optical Tweezers