title: The optical stretcher: a novel laser tool to micromanipulate cells.
abstract: When a dielectric object is placed between two opposed, nonfocused laser beams, the total force acting on the object is zero but the surface forces are additive, thus leading to a stretching of the object along the axis of the beams. Using this principle, we have constructed a device, called an optical stretcher, that can be used to measure the viscoelastic properties of dielectric materials, including biologic materials such as cells, with the sensitivity necessary to distinguish even between different individual cytoskeletal phenotypes. We have successfully used the optical stretcher to deform human erythrocytes and mouse fibroblasts. In the optical stretcher, no focusing is required, thus radiation damage is minimized and the surface forces are not limited by the light power. The magnitude of the deforming forces in the optical stretcher thus bridges the gap between optical tweezers and atomic force microscopy for the study of biologic materials.
authors.affiliation: Center for Nonlinear Dynamics, Department of Physics, University of Texas at Austin, Texas 78712, USA. jguck@chaos.ph.utexas.edu
authors.forename: J
authors.initials: J
authors.lastname: Guck
authors.forename: R
authors.initials: R
authors.lastname: Ananthakrishnan
authors.forename: H
authors.initials: H
authors.lastname: Mahmood
authors.forename: T J
authors.initials: TJ
authors.lastname: Moon
authors.forename: C C
authors.initials: CC
authors.lastname: Cunningham
authors.forename: J
authors.initials: J
authors.lastname: Käs
mesh_terms: D016475:3T3 Cells; D000465:Algorithms; D000818:Animals; D048429:Cell Size / Q000528:radiation effects; D003599:Cytoskeleton / Q000528:radiation effects; D004548:Elasticity / Q000528:radiation effects; D004912:Erythrocytes / Q000166:cytology* / Q000528:radiation effects*; D005347:Fibroblasts / Q000166:cytology* / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D051379:Mice; D008858:Microscopy, Phase-Contrast; D008863:Microspheres; D012822:Silicon Dioxide; D014783:Viscosity / Q000528:radiation effects
chemical_list: D012822:Silicon Dioxide