Berlin 2018 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 15: Postersession III
BP 15.15: Poster
Dienstag, 13. März 2018, 14:00–16:00, Poster B
Dynamic Optical Displacement Spectroscopy to Explore Ultrafast Bio-Membrane Dynamics — •Cornelia Monzel1,2,5, Daniel Schmidt3,4, Ana-Suncana Smith3, Udo Seifert4, Kheya Sengupta2, and Rudolf Merkel1 — 1Forschungszentrum Jülich, Institute of Complex Systems 7, 52428 Jülich — 2Université Aix-Marseille, CNRS UMR 7325 (CINaM), 13288 Marseille — 3FAU Erlangen, EAM, 91052 Erlangen — 4Universität Stuttgart, II. Institut für Theoretische Physik, 70550 Stuttgart — 5present address: University of Düsseldorf, Department of Physics, 40225 Düsseldorf
The cell membrane not only forms a mechanical barrier, but is also involved in processes such as cell shape regulation, endo-/exocytosis, adhesion or membrane ruffling. To enable these physiological functions the membrane has to be soft and easily deformable, it exhibits active deformations and thermal fluctuations. Here we explore the nature of membrane fluctuations in model systems and cells with a novel method, called Dynamic Optical Displacement Spectroscopy (DODS). Based on a conventional Fluorescence Correlation Spectroscopy setup, this new approach combines the sensitivity of focal spot measurements (spatial detection limit of 20 nm) with a high dynamic range (10−5-10 s). We validate DODS on giant unilamellar vesicles and derive fluctuation amplitude, membrane tension, and hydrodynamic damping with an extended membrane theory accounting for the experimental resolution. Moreover, we use DODS to quantify ATP-dependent membrane dynamics in red blood cells and effects of γ-interferon priming on the ruffling behavior of human macrophages.