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single particle tracking

Kuangcai Chen, Yan Gu, Wei Sun, Bin Dong, Gufeng Wang, Xinxin Fan, Tian Xia, Ning Fang
We report an automated single particle tracking technique for tracking the x, y, z coordinates, azimuthal and elevation angles of anisotropic plasmonic gold nanorod probes in live cells. These five spatial coordinates are collectively referred to as 5D. This method overcomes a long-standing challenge in distinguishing rotational motions from translational motions in the z-axis in differential interference contrast microscopy to result in full disclosure of nanoscale motions with high accuracy. Transferrin-coated endocytic gold nanorod cargoes initially undergo active rotational diffusion and display characteristic rotational motions on the membrane...
October 12, 2017: Nature Communications
Han-Yuan Liu, Wei-Liang Chen, Christopher Kemper Ober, Susan Daniel
Reconstituted supported lipid bilayers (SLB) are widely used as in vitro cell-surface models because they are compatible with a variety of surface based analytical techniques. However, one of the challenges of using SLBs as a model of the cell surface is the limited complexity in membrane composition, including the incorporation of transmembrane proteins and lipid diversity that may impact the activity of those proteins. Additionally, it is challenging to preserve the transmembrane protein native orientation, function, and mobility in SLBs...
October 11, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Esther H Yang, Julia Rode, Md Amran Howlader, Marina Eckermann, Jobette T Santos, Daniel Hernandez Armada, Ruixiang Zheng, Chunxia Zou, Christopher W Cairo
Glycoprotein receptors are influenced by myriad intermolecular interactions at the cell surface. Specific glycan structures may interact with endogenous lectins that enforce or disrupt receptor-receptor interactions. Glycoproteins bound by multivalent lectins may form extended oligomers or lattices, altering the lateral mobility of the receptor and influencing its function through endocytosis or changes in activation. In this study, we have examined the interaction of Galectin-3 (Gal-3), a human lectin, with adhesion receptors...
2017: PloS One
Kan Xiong, Paul C Blainey
We describe a simple, robust and high throughput single molecule flow-stretching assay for studying 1D diffusion of molecules along DNA. In this assay, glass coverslips are functionalized in a one-step reaction with silane-PEG-biotin. Flow cells are constructed by sandwiching an adhesive tape with pre-cut channels between a functionalized coverslip and a PDMS slab containing inlet and outlet holes. Multiple channels are integrated into one flow cell and the flow of reagents into each channel can be fully automated, which significantly increases the assay throughput and reduces hands-on time per assay...
October 1, 2017: Journal of Visualized Experiments: JoVE
P Bilski, B Marczewska, W Gieszczyk, M Klosowski, T Nowak, M Naruszewicz
Radiophotoluminescence signal of LiF crystals was found to be sufficiently strong to visualize tracks of a single charged particle. This was achieved with a wide-field fluorescent microscope equipped with a ×100 objective and LiF single crystals grown with the Czochralski method at IFJ PAN. The tracks of alpha particles, protons, as well as products of 6Li(n,α)3H reaction with thermal neutrons (moderated Pu/Be source), were observed. These encouraging results are the first steps towards practical use of LiF as fluorescent nuclear track detectors...
August 30, 2017: Radiation Protection Dosimetry
Ali Moridnejad, Thomas C Preston, Ulrich K Krieger
Morphology-dependent resonances (MDRs) can serve as a sensitive probe of the size and composition of microspheres. While the utilization of MDRs to characterize homogeneous spheres is now routine, analysis of spherical particles with more complicated refractive index profiles can be extremely difficult and time consuming. In ultraviscous and glassy aerosol particles, the concentration profile of water during sorption often contains a sharp front that propagates from the particle surface to the particle center over time...
October 16, 2017: Journal of Physical Chemistry. A
Juyeong Kim, Zihao Ou, Matthew R Jones, Xiaohui Song, Qian Chen
Numerous mechanisms have been studied for chemical reactions to provide quantitative predictions on how atoms spatially arrange into molecules. In nanoscale colloidal systems, however, less is known about the physical rules governing their spatial organization, i.e., self-assembly, into functional materials. Here, we monitor real-time self-assembly dynamics at the single nanoparticle level, which reveal marked similarities to foundational principles of polymerization. Specifically, using the prototypical system of gold triangular nanoprisms, we show that colloidal self-assembly is analogous to polymerization in three aspects: ensemble growth statistics following models for step-growth polymerization, with nanoparticles as linkable "monomers"; bond angles determined by directional internanoparticle interactions; and product topology determined by the valency of monomeric units...
October 2, 2017: Nature Communications
Yun Yu, Vignesh Sundaresan, Sabyasachi Bandyopadhyay, Yulun Zhang, Martin A Edwards, Kim McKelvey, Henry S White, Katherine A Willets
Controlled three-dimensional positioning of nanoparticles is achieved by delivering single fluorescent nanoparticles from a nanopipette and capturing them at well-defined regions of an electrified substrate. To control the position of single nanoparticles, the force of the pressure-driven flow from the pipette is balanced by the attractive electrostatic force at the substrate, providing a strategy by which nanoparticle trajectories can be manipulated in real time. To visualize nanoparticle motion, a resistive-pulse electrochemical setup is coupled with an optical microscope, and nanoparticle trajectories are tracked in three dimensions using super-resolution fluorescence imaging to obtain positional information with precision in the tens of nanometers...
October 5, 2017: ACS Nano
Do-Hyeon Kim, Dong-Kyun Kim, Kai Zhou, Soyeon Park, Yonghoon Kwon, Min Gyu Jeong, Nam Ki Lee, Sung Ho Ryu
Cellular processes occur through the orchestration of multi-step molecular reactions. Reaction progress kinetic analysis (RPKA) can provide the mechanistic details to elucidate the multi-step molecular reactions. However, current tools have limited ability to simultaneously monitor dynamic variations in multiple complex states at the single molecule level to apply RPKA in living cells. In this research, a single particle tracking-based reaction progress kinetic analysis (sptRPKA) was developed to simultaneously determine the kinetics of multiple states of protein complexes in the membrane of a single living cell...
July 1, 2017: Chemical Science
Peng Cheng, Sissy M Jhiang, Chia-Hsiang Menq
Back focal plane (BFP) interferometry is frequently used to detect the motion of a single laser trapped bead in a photonic force microscope (PFM) system. Whereas this method enables high-speed and high-resolution position measurement, its measurement range is limited by nonlinearity coupled with crosstalk in three-dimensional (3-D) measurement, and validation of its measurement accuracy is not trivial. This Letter presents an automated calibration system in conjunction with a 3-D quadratic model to render rapid and accurate calibration of the laser measurement system...
October 1, 2017: Optics Letters
Yuan Gao, Stephen M Anthony, Yi Yi, Wenqian Li, Yanqi Yu, Yan Yu
Endosomes in cells are known to move directionally along microtubules, but their rotational dynamics have rarely been investigated. Even less is known, specifically, about the rotation of non-spherical endosomes. Here we report a single-Janus rod rotational tracking study to reveal the rich rotational dynamics of rod-shaped endosomes in living cells. The rotational reporters were Janus rods that display patches of different fluorescent colors on the opposite sides along their long axes. When wrapped tightly inside endosomes, the shape and optical anisotropy of these Janus rods enable the simultaneous measurements of all three rotational angles (in-plane, out-of-plane, and longitudinal) and the translational motion of single endosomes with high spatiotemporal resolutions...
September 25, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Pascal Vallotton, Antoine M van Oijen, Cynthia B Whitchurch, Vladimir Gelfand, Leslie Yeo, Georgios Tsiavaliaris, Stephanie Heinrich, Elisa Dultz, Karsten Weis, David Grünwald
Object tracking is an instrumental tool supporting studies of cellular trafficking. There are three challenges in object tracking: the identification of targets; the precise determination of their position and boundaries, and the assembly of correct trajectories. This last challenge is particularly relevant when dealing with densely populated images with low signal-to-noise ratios - conditions that are often encountered in applications such as organelle tracking, virus particle tracking, or single-molecule imaging...
September 25, 2017: Traffic
María Cecilia De Rossi, Diana E Wetzler, Lorena Benseñor, María Emilia De Rossi, Mariela Sued, Daniela Rodríguez, Vladimir Gelfand, Luciana Bruno, Valeria Levi
BACKGROUND: Intracellular transport requires molecular motors that step along cytoskeletal filaments actively dragging cargoes through the crowded cytoplasm. Here, we explore the interplay of the opposed polarity motors kinesin-1 and cytoplasmic dynein during peroxisome transport along microtubules in Drosophila S2 cells. METHODS: We used single particle tracking with nanometer accuracy and millisecond time resolution to extract quantitative information on the bidirectional motion of organelles...
September 19, 2017: Biochimica et Biophysica Acta
Amin Feizpour, David N Stelter, Crystal Wong, Hisashi Akiyama, Suryaram Gummuluru, Tom Keyes, Bjoern M Reinhard
Viral membranes are nanomaterials whose fluidity depends on their composition, in particular the cholesterol (chol) content. As differences in the membrane composition of individual virus particles can lead to different intracellular fates, biophysical tools capable of sensing the membrane fluidity on the single-virus level are required. In this manuscript, we demonstrate that fluctuations in the polarization of light scattered off gold or silver nanoparticle (NP)-labeled virus-like-particles (VLPs) encode information about the membrane fluidity of individual VLPs...
September 21, 2017: ACS Sensors
G Sikora, E Kepten, A Weron, M Balcerek, K Burnecki
Modern live-imaging fluorescent microscopy techniques following the stochastic motion of labeled tracer particles, i.e. single particle tracking (SPT) experiments, have uncovered significant deviations from the laws of Brownian motion in a variety of biological systems. Accurately characterizing the anomalous diffusion for SPT experiments has become a central issue in biophysics. However, measurement errors raise difficulty in the analysis of single trajectories. In this paper, we introduce a novel surface calibration method based on a fractionally integrated moving average (FIMA) process as an effective tool for extracting both the magnitude of the measurement error and the anomalous exponent for autocorrelated processes of various origins...
October 11, 2017: Physical Chemistry Chemical Physics: PCCP
Zach Marin, J Kent Wallace, Jay Nadeau, Andre Khalil
We propose an automated wavelet-based method of tracking particles in unreconstructed off-axis holograms to provide rough estimates of the presence of motion and particle trajectories in digital holographic microscopy (DHM) time series. The wavelet transform modulus maxima segmentation method is adapted and tailored to extract Airy-like diffraction disks, which represent bacteria, from DHM time series. In this exploratory analysis, the method shows potential for estimating bacterial tracks in low-particle-density time series, based on a preliminary analysis of both living and dead Serratia marcescens, and for rapidly providing a single-bit answer to whether a sample chamber contains living or dead microbes or is empty...
September 13, 2017: Methods: a Companion to Methods in Enzymology
Michele R Plewes, Patrick D Burns, Richard M Hyslop, B George Barisas
Fish oil is a rich source of omega-3 fatty acids which disrupt lipid microdomain structure and affect mobility of the prostaglandin F2α (FP) receptor in bovine luteal cells. The objectives of this study were to determine the effects of individual omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on 1) membrane fatty acid composition, 2) lipid microdomain structure, and 3) lateral mobility of the FP receptor in bovine luteal cells. Ovaries were collected from a local abattoir (n=5/experiment)...
September 11, 2017: Biochimica et Biophysica Acta
Marie-Lena I E Harwardt, Phoebe Young, Willem M Bleymüller, Timo Meyer, Christos Karathanasis, Hartmut H Niemann, Mike Heilemann, Marina S Dietz
The human MET receptor tyrosine kinase contributes to vertebrate development and cell proliferation. As a proto-oncogene, it is a target in cancer therapies. MET is also relevant for bacterial infection by Listeria monocytogenes and is activated by the bacterial protein internalin B. The processes of ligand binding, receptor activation, and the diffusion behavior of MET within the plasma membrane as well as its interconnections with various cell components are not fully understood. We investigated the receptor diffusion dynamics using single-particle tracking and imaging fluorescence correlation spectroscopy and elucidated mobility states of resting and internalin B-bound MET...
September 2017: FEBS Open Bio
Caroline E Wagner, Bradley S Turner, Michael Rubinstein, Gareth H McKinley, Katharina Ribbeck
The details of how a mucus hydrogel forms from its primary structural component, mucin polymers, remain incompletely resolved. To explore this, we use a combination of macrorheology and single-particle tracking to investigate the bulk and microscopic mechanical properties of reconstituted MUC5AC mucin gels. We find that analyses of thermal fluctuations on the length scale of the micrometer-sized particles are not predictive of the linear viscoelastic response of the mucin gels, and that taken together, the results from both techniques help to provide complementary insight into the structure of the network...
October 2, 2017: Biomacromolecules
Frank C Hendriks, Florian Meirer, Alexey V Kubarev, Zoran Ristanović, Maarten B J Roeffaers, Eelco T C Vogt, Pieter C A Bruijnincx, Bert M Weckhuysen
We used single-molecule fluorescence microscopy to study self-diffusion of a feedstock-like probe molecule with nanometer accuracy in the macropores of a micrometer-sized, real-life fluid catalytic cracking (FCC) particle. Movies of single fluorescent molecules allowed their movement through the pore network to be reconstructed. The observed tracks were classified into three different states by machine learning and all found to be distributed homogeneously over the particle. Most probe molecules (88%) were immobile, with the molecule most likely being physisorbed or trapped; the remainder was either mobile (8%), with the molecule moving inside the macropores, or showed hybrid behavior (4%)...
October 4, 2017: Journal of the American Chemical Society
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