title: Dispersion-relation phase spectroscopy of intracellular transport.
abstract: We used quantitative phase imaging to measure the dispersion relation, i.e. decay rate vs. spatial mode, associated with mass transport in live cells. This approach applies equally well to both discrete and continuous mass distributions without the need for particle tracking. From the quadratic experimental curve specific to diffusion, we extracted the diffusion coefficient as the only fitting parameter. The linear portion of the dispersion relation reveals the deterministic component of the intracellular transport. Our data show a universal behavior where the intracellular transport is diffusive at small scales and deterministic at large scales. Measurements by our method and particle tracking show that, on average, the mass transport in the nucleus is slower than in the cytoplasm.
authors: Quantitative Light Imaging Laboratory, Department of Mechanical and Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801,USA.
authors: Ru
authors: R
authors: Wang
authors: Zhuo
authors: Z
authors: Wang
authors: Larry
authors: L
authors: Millet
authors: Martha U
authors: MU
authors: Gillette
authors: A J
authors: AJ
authors: Levine
authors: Gabriel
authors: G
authors: Popescu
mesh_terms: D000465:Algorithms; D000818:Animals; D001692:Biological Transport; D001709:Biotechnology / Q000379:methods; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D004058:Diffusion; D004867:Equipment Design; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D008027:Light; D017628:Microglia / Q000378:metabolism; D008857:Microscopy, Interference / Q000379:methods; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D055095:Optics and Photonics; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000379:methods