title: Nanoscopy of bacterial cells immobilized by holographic optical tweezers.
abstract: Imaging non-adherent cells by super-resolution far-field fluorescence microscopy is currently not possible because of their rapid movement while in suspension. Holographic optical tweezers (HOTs) enable the ability to freely control the number and position of optical traps, thus facilitating the unrestricted manipulation of cells in a volume around the focal plane. Here we show that immobilizing non-adherent cells by optical tweezers is sufficient to achieve optical resolution well below the diffraction limit using localization microscopy. Individual cells can be oriented arbitrarily but preferably either horizontally or vertically relative to the microscope's image plane, enabling access to sample sections that are impossible to achieve with conventional sample preparation and immobilization. This opens up new opportunities to super-resolve the nanoscale organization of chromosomal DNA in individual bacterial cells.
authors.affiliation: Biomolecular Photonics, Department of Physics, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany.
authors.forename: Robin
authors.initials: R
authors.lastname: Diekmann
authors.affiliation: NSF Center for Biophotonics, University of California, 2700 Stockton Boulevard, Suite 1400, Davis, Sacramento, California 95817, USA.|Department of Physics and Technology, UiT The Arctic University of Norway, Klokkargårdsbakken 35, 9019 Tromsø, Norway.
authors.forename: Deanna L
authors.initials: DL
authors.lastname: Wolfson
authors.affiliation: Institute of Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Spahn
authors.affiliation: Institute of Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt, Germany.
authors.forename: Mike
authors.initials: M
authors.lastname: Heilemann
authors.affiliation: Biomolecular Photonics, Department of Physics, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Schüttpelz
authors.affiliation: Biomolecular Photonics, Department of Physics, University of Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany.|NSF Center for Biophotonics, University of California, 2700 Stockton Boulevard, Suite 1400, Davis, Sacramento, California 95817, USA.
authors.forename: Thomas
authors.identifier: 0000-0003-2348-7416
authors.initials: T
authors.lastname: Huser
mesh_terms: D004926:Escherichia coli / Q000648:ultrastructure*; D008856:Microscopy, Fluorescence / Q000379:methods*; D052898:Optical Tweezers