title: Measuring fast stochastic displacements of bio-membranes with dynamic optical displacement spectroscopy.
abstract: Stochastic displacements or fluctuations of biological membranes are increasingly recognized as an important aspect of many physiological processes, but hitherto their precise quantification in living cells was limited due to a lack of tools to accurately record them. Here we introduce a novel technique--dynamic optical displacement spectroscopy (DODS), to measure stochastic displacements of membranes with unprecedented combined spatiotemporal resolution of 20 nm and 10 μs. The technique was validated by measuring bending fluctuations of model membranes. DODS was then used to explore the fluctuations in human red blood cells, which showed an ATP-induced enhancement of non-Gaussian behaviour. Plasma membrane fluctuations of human macrophages were quantified to this accuracy for the first time. Stimulation with a cytokine enhanced non-Gaussian contributions to these fluctuations. Simplicity of implementation, and high accuracy make DODS a promising tool for comprehensive understanding of stochastic membrane processes.
authors.affiliation: Institute of Complex Systems 7 (ICS-7): Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.|Aix-Marseille Université, CNRS, Centre Interdisciplinaire de Nanoscience de Marseille UMR 7325, 13288 Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Monzel
authors.affiliation: Institut für Theoretische Physik, Department für Physik, and the Excellence Cluster: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.|II. Institut für Theoretische Physik, Fakultät 8: Mathematik und Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Schmidt
authors.affiliation: Institute of Complex Systems 7 (ICS-7): Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kleusch
authors.affiliation: Institute of Complex Systems 7 (ICS-7): Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Kirchenbüchler
authors.affiliation: II. Institut für Theoretische Physik, Fakultät 8: Mathematik und Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Seifert
authors.affiliation: Institut für Theoretische Physik, Department für Physik, and the Excellence Cluster: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.|Division of Physical Chemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
authors.forename: A-S
authors.initials: AS
authors.lastname: Smith
authors.affiliation: Aix-Marseille Université, CNRS, Centre Interdisciplinaire de Nanoscience de Marseille UMR 7325, 13288 Marseille, France.
authors.forename: K
authors.initials: K
authors.lastname: Sengupta
authors.affiliation: Institute of Complex Systems 7 (ICS-7): Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: R
authors.identifier: http://orcid.org/0000-0003-3178-3282
authors.initials: R
authors.lastname: Merkel
mesh_terms: D002462:Cell Membrane / Q000502:physiology; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000502:physiology*; D018613:Microscopy, Confocal; D008954:Models, Biological; D061848:Optical Imaging / Q000379:methods*; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis / Q000379:methods*; D013269:Stochastic Processes; D053835:Unilamellar Liposomes
chemical_list: D053835:Unilamellar Liposomes