Twisting biological objects by optical tweezers

P. Ormos, H. van Amerongen, S. Bottka, P. Galaja, G. Garab, H. Kirei, L. Oroszi

Research output: Chapter in Book/Report/Conference proceedingConference paper

1 Citation (Scopus)


We describe a novel method by which it is possible to apply and measure torque directly on particles grabbed in optical tweezers. It can be used to orient particles of micron size or even on single molecules, biopolymers by the use of test particles.The procedure is based on the observation that flat objects are oriented in an optical trap formed by linearly polarized light. The orienting torque originates from the anisotropic scattering of polarized light by the trapped particle. The phenomenon is characterized in detail, the physics is analysed. A tool is developed that exploits this effect to manuipulate biological macromolecules. Microscopic particles are produced by photopolymerisation that exploit this orientation effect and by which the torque is applied upon the biological object. In our system the applied torque can be turned on and off, it is controlled independently of the grabbing force of the tweezers during the manipulation process. The capabilities of the method are demonstrated. The method has great promise for application on DNA, DNA-protein complexes, actin filaments and other biopolymers
Original languageEnglish
Title of host publicationOptical Trapping and Optical Micromanipulation, Proceedings of SPIE, Bellingham, 2005
EditorsK. Dholakia, G.C. Spalding
Place of PublicationBellingham
Publication statusPublished - 2005
EventSPIE 2005 -
Duration: 15 Jun 200516 Jun 2005


ConferenceSPIE 2005

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