title: Diffusive and directional intracellular dynamics measured by field-based dynamic light scattering.
abstract: Quantitative measurement of diffusive and directional processes of intracellular structures is not only critical in understanding cell mechanics and functions, but also has many applications, such as investigation of cellular responses to therapeutic agents. We introduce a label-free optical technique that allows non-perturbative characterization of localized intracellular dynamics. The method combines a field-based dynamic light scattering analysis with a confocal interferometric microscope to provide a statistical measure of the diffusive and directional motion of scattering structures inside a microscopic probe volume. To demonstrate the potential of this technique, we examined the localized intracellular dynamics in human epithelial ovarian cancer cells. We observed the distinctive temporal regimes of intracellular dynamics, which transitions from random to directional processes on a timescale of ~0.01 sec. In addition, we observed disrupted directional processes on the timescale of 1 approximately 5 sec by the application of a microtubule polymerization inhibitor, Colchicine, and ATP depletion.
authors.affiliation: Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
authors.forename: Chulmin
authors.initials: C
authors.lastname: Joo
authors.forename: Conor L
authors.initials: CL
authors.lastname: Evans
authors.forename: Thomas
authors.initials: T
authors.lastname: Stepinac
authors.forename: Tayyaba
authors.initials: T
authors.lastname: Hasan
authors.forename: Johannes F
authors.initials: JF
authors.lastname: de Boer
mesh_terms: D045744:Cell Line, Tumor; D003078:Colchicine / Q000494:pharmacology; D004058:Diffusion / Q000187:drug effects; D004655:Emulsions; D006801:Humans; D007368:Interferometry / Q000379:methods*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D008027:Light; D008858:Microscopy, Phase-Contrast; D009038:Motion; D012542:Scattering, Radiation; D013997:Time Factors; D041623:Tomography, Optical Coherence
chemical_list: D004655:Emulsions; D003078:Colchicine