Abstract
The radiation pressure of two counter-propagating laser beamstraps and stretches individual biological cells. Using non-focused laser beams, cells stay viable when irradiated withup to 1.4 W of 780 nm Ti-sapphire laser light for severalminutes. Fluorescence microscopy has demonstrated that theessential features of the cytoskeleton, excluding stressfibres, are maintained for stretched cells in suspension. Theoptical stretcher provides accurate measurements of whole cell elasticity and thus can distinguish between different cells bytheir cytoskeletal characteristics. A model has been derivedfor the forces on the surface of a spherical cell that explainsthe observed deformations. The peak stresses on the surface ofcells are 1-150 Pa for light powers of 0.2-1.4 W anddepending on the refractive index of the cell trapped. Precursors of rat nerve cells exhibit a homogeneous Young'smodulus E of 500±25 Pa,whereas for osmotically inflated, spherical red blood cells(RBCs) the homogeneous Young's modulus isE = 11.0±0.5 Pa. Thus, PC12cells are about 40-50 times more elastic than RBCs.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
