title: Dual-modality single particle orientation and rotational tracking of intracellular transport of nanocargos.
abstract: The single particle orientation and rotational tracking (SPORT) technique was introduced recently to follow the rotational motion of plasmonic gold nanorod under a differential interference contrast (DIC) microscope. In biological studies, however, cellular activities usually involve a multiplicity of molecules; thus, tracking the motion of a single molecule/object is insufficient. Fluorescence-based techniques have long been used to follow the spatial and temporal distributions of biomolecules of interest thanks to the availability of multiplexing fluorescent probes. To know the type and number of molecules and the timing of their involvement in a biological process under investigation by SPORT, we constructed a dual-modality DIC/fluorescence microscope to simultaneously image fluorescently tagged biomolecules and plasmonic nanoprobes in living cells. With the dual-modality SPORT technique, the microtubule-based intracellular transport can be unambiguously identified while the dynamic orientation of nanometer-sized cargos can be monitored at video rate. Furthermore, the active transport on the microtubule can be easily separated from the diffusion before the nanocargo docks on the microtubule or after it undocks from the microtubule. The potential of dual-modality SPORT is demonstrated for shedding new light on unresolved questions in intracellular transport.
authors.affiliation: Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Gu
authors.forename: Gufeng
authors.initials: G
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Fang
mesh_terms: D001692:Biological Transport; D004058:Diffusion; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008856:Microscopy, Fluorescence; D008857:Microscopy, Interference; D008870:Microtubules / Q000648:ultrastructure; D015335:Molecular Probes / Q000737:chemistry*; D036103:Nanotechnology; D043942:Nanotubes / Q000032:analysis* / Q000648:ultrastructure*
chemical_list: D015335:Molecular Probes; D006046:Gold