Read by QxMD icon Read

single particle tracking

Christopher Batchelor-McAuley, Christopher A Little, Stanislav V Sokolov, Enno Kätelhön, Giorgia Zampardi, Richard G Compton
The lipid soluble fluorophore Nile Red (9-diethylamino-5-benzo[α]phenoxazinone) is used to fluorescently and electrochemically label an organic-in-water emulsion, where the organic phase is an ionic liquid [P6,6,6,14][FAP]/toluene mixture. The optical detection of the individual droplets is enabled facilitating the in-situ tracking and sizing of the suspended particles (average diameter = 530 nm, interquartile range = 180 nm). Through the use of a combined thin-layer optical/electrochemical cell, the irreversible accumulation of the droplets at an optically opaque carbon fibre electrode (diameter ~ 7...
October 17, 2016: Analytical Chemistry
Maria Goiko, John R de Bruyn, Bryan Heit
The plasma membrane is a heterogeneous environment characterized by anomalous diffusion and the presence of microdomains that are molecularly distinct from the bulk membrane. Using single particle tracking of the C-type lectin CD93, we have identified for the first time the transient trapping of transmembrane proteins in cage-like microdomains which restrict protein diffusion. These cages are stabilized by actin-dependent confinement regions, but are separate structures with sizes and lifespans uncorrelated to those of the underlying actin corral...
October 11, 2016: Scientific Reports
Aleem Syed, Qiaochu Zhu, Emily A Smith
The effect of ligand on the lateral diffusion of receptor for advanced glycation endproducts (RAGE), a receptor involved in numerous pathological conditions, remains unknown. Single particle tracking experiments that use quantum dots specifically bound to hemagglutinin (HA)-tagged RAGE (HA-RAGE) are reported to elucidate the effect of ligand binding on HA-RAGE diffusion in GM07373 cell membranes. The ligand used in these studies is methylglyoxal modified-bovine serum albumin (MGO-BSA) containing advanced glycation end products modifications...
October 7, 2016: Biochimica et Biophysica Acta
Firoozeh Babayekhorasani, Dave E Dunstan, Ramanan Krishnamoorti, Jacinta C Conrad
We identify distinct mechanisms controlling slowing of nanoparticle diffusion through complex media featuring both rigid geometrical confinement and soft mobile crowders. Towards this end, we use confocal microscopy and single particle tracking to probe the diffusion of 400 nm nanoparticles suspended in Newtonian water, in a Newtonian glycerol/water mixture, or in a non-Newtonian polymer solution through a model porous medium, a packed bed of microscale glass beads. The mobility of nanoparticles, as quantified by the long-time diffusion coefficient extracted from the particle mean-squared displacement, slows as the average pore size of the packed bed media decreases for both Newtonian and non-Newtonian solutions...
October 12, 2016: Soft Matter
Roozbeh Abedini-Nassab, Daniel Y Joh, Faris Albarghouthi, Ashutosh Chilkoti, David M Murdoch, Benjamin B Yellen
The ability to direct and sort individual biological and non-biological particles into spatially addressable locations is fundamentally important to the emerging field of single cell biology. Towards this goal, we demonstrate a new class of magnetophoretic transistors, which can switch single magnetically labeled cells and magnetic beads between different paths in a microfluidic chamber. Compared with prior work on magnetophoretic transistors driven by a two-dimensional in-plane rotating field, the addition of a vertical magnetic field bias provides significant advantages in preventing the formation of particle clumps and in better replicating the operating principles of circuits in general...
October 18, 2016: Lab on a Chip
Jean-Yves Tinevez, Nick Perry, Johannes Schindelin, Genevieve M Hoopes, Gregory D Reynolds, Emmanuel Laplantine, Sebastian Y Bednarek, Spencer L Shorte, Kevin W Eliceiri
We present TrackMate, an open source Fiji plugin for the automated, semi-automated, and manual tracking of single-particles. It offers a versatile and modular solution that works out of the box for end users, through a simple and intuitive user interface. It is also easily scriptable and adaptable, operating equally well on 1D over time, 2D over time, 3D over time, or other single and multi-channel image variants. TrackMate provides several visualization and analysis tools that aid in assessing the relevance of results...
October 3, 2016: Methods: a Companion to Methods in Enzymology
Trevor T Ashley, Eric L Gan, Jane Pan, Sean B Andersson
The ability to track single fluorescent particles in three-dimensions with sub-diffraction limit precision as well as sub-millisecond temporal resolution has enabled the understanding of many biophysical phenomena at the nanometer scale. While there are several techniques for achieving this, most require complicated experimental setups that are expensive to implement. These methods can offer superb performance but their complexity may be overwhelming to the end-user whose aim is only to understand the feature being imaged...
September 1, 2016: Biomedical Optics Express
David Albrecht, Christian M Winterflood, Mohsen Sadeghi, Thomas Tschager, Frank Noé, Helge Ewers
The axon initial segment (AIS) is enriched in specific adaptor, cytoskeletal, and transmembrane molecules. During AIS establishment, a membrane diffusion barrier is formed between the axonal and somatodendritic domains. Recently, an axonal periodic pattern of actin, spectrin, and ankyrin forming 190-nm-spaced, ring-like structures has been discovered. However, whether this structure is related to the diffusion barrier function is unclear. Here, we performed single-particle tracking time-course experiments on hippocampal neurons during AIS development...
October 10, 2016: Journal of Cell Biology
Yu-Mei Huang, Matthew N Rasband
What prevents the movement of membrane molecules between axonal and somatodendritic domains is unclear. In this issue, Albrecht et. al. (2016. J. Cell Biol. demonstrate via high-speed single-particle tracking and superresolution microscopy that lipid-anchored molecules in the axon initial segment are confined to membrane domains separated by periodically spaced actin rings.
October 10, 2016: Journal of Cell Biology
Donald W Lee, Hung-Lun Hsu, Kaitlyn B Bacon, Susan Daniel
With the development of single-particle tracking (SPT) microscopy and host membrane mimics called supported lipid bilayers (SLBs), stochastic virus-membrane binding interactions can be studied in depth while maintaining control over host receptor type and concentration. However, several experimental design challenges and quantitative image analysis limitations prevent the widespread use of this approach. One main challenge of SPT studies is the low signal-to-noise ratio of SPT videos, which is sometimes inevitable due to small particle sizes, low quantum yield of fluorescent dyes, and photobleaching...
2016: PloS One
Seyed R Tabaei, Jurriaan J J Gillissen, Nam-Joon Cho
Particle tracking is used to measure the diffusional motion of nanosized (≈100 nm), lipid vesicles that are electrostatically adsorbed onto a solid supported lipid bilayer. It is found that the motion of membrane-adhering vesicles is Brownian and depends inversely on the vesicle size, but is insensitive to the vesicle surface charge. The measured diffusivity agrees well with the Evans-Sackmann model for the diffusion of inclusions in supported, fluidic membranes. The agreement implies that the vesicle motion is coupled to that of a nanoscopic lipid cluster in the upper leaflet, which slides over the lower leaflet...
September 30, 2016: Small
Otto L J Virtanen, Ashvini Purohit, Monia Brugnoni, Dominik Wöll, Walter Richtering
Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this work, we use single particle tracking of fluorescently labeled PNIPAM microgels as a showcase for tuning microgel size by a rapid non-stirred precipitation polymerization procedure. This approach is well suited for prototyping new reaction compositions and conditions or for applications that do not require large amounts of product. Microgel synthesis, particle size and structure determination by dynamic and static light scattering are detailed in the protocol...
2016: Journal of Visualized Experiments: JoVE
Shalin B Mehta, Molly McQuilken, Patrick J La Riviere, Patricia Occhipinti, Amitabh Verma, Rudolf Oldenbourg, Amy S Gladfelter, Tomomi Tani
Regulation of order, such as orientation and conformation, drives the function of most molecular assemblies in living cells but remains difficult to measure accurately through space and time. We built an instantaneous fluorescence polarization microscope, which simultaneously images position and orientation of fluorophores in living cells with single-molecule sensitivity and a time resolution of 100 ms. We developed image acquisition and analysis methods to track single particles that interact with higher-order assemblies of molecules...
September 27, 2016: Proceedings of the National Academy of Sciences of the United States of America
Yoshiaki Okamoto, Toshinori Motegi, Kohei Morita, Toshiyuki Takagi, Hideki Amii, Toshiyuki Kanamori, Masashi Sonoyama, Ryugo Tero
Fluorinated lipids and surfactants are attractive biomimetic materials for the extraction and reorganization of membrane proteins because of the biological inertness of fluorocarbons. We investigated the fundamental physical properties of a partially fluorinated phospholipid (F4-DMPC), such as phase transition, area thermal expansion, and lateral lipid diffusion, to evaluate the intermolecular interaction of F4-DMPC in the hydrophobic region quantitatively on the basis of free-volume theory. Fluorescence microscope observation of the supported lipid bilayer (SLB) of F4-DMPC showed that the phase transition between the liquid crystalline and gel phases occurred at 5 °C and that the area thermal expansion coefficient was independent of the temperature near the phase transition temperature...
October 4, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Bharath Bangalore Rajeeva, Derek S Hernandez, Mingsong Wang, Evan Perillo, Linhan Lin, Leonardo Scarabelli, Bharadwaj Pingali, Luis M Liz-Marzán, Andrew K Dunn, Jason B Shear, Yuebing Zheng
Selective localization of biomolecules at the hot spots of a plasmonic nanoparticle is an attractive strategy to exploit the light-matter interaction due to the high field concentration. Current approaches for hot spot targeting are time-consuming and involve prior knowledge of the hot spots. Multiphoton plasmonic lithography is employed to rapidly immobilize bovine serum albumin (BSA) hydrogel at the hot spot tips of a single gold nanotriangle (AuNT). Regioselectivity and quantity control by manipulating the polarization and intensity of the incident laser are also established...
November 2015: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Satbir Singh, Pawan Kumar, Benny Abraham Kaipparettu, Bipin Kumar Gupta
Herein, we introduce a novel strategy for the synthesis of Eu(3+) doped α-sodium gadolinium fluoride (α-NaGd0.88F4:Eu0.12 (3+)) based luminomagnetic nanophosphors using hydrothermal route. The synthesized nanophosphor has exceptional luminescent and paramagnetic properties in a single host lattice, which is highly desirable for biomedical applications. This highly luminescent nanophosphor with an average particle size ∼ 5±3 nm enables high-contrast fluorescent imaging with decreased light scattering. In vitro cellular uptake is shown by fluorescent microscopy that envisages the characteristic hypersensitive red emission of Eu(3+) doped α-sodium gadolinium fluoride centered at 608 nm ((5)D0-(7)F2) upon 465 nm excitation wavelength...
2016: RSC Advances
M R Plewes, P D Burns, P E Graham, R M Hyslop, B G Barisas
Lipid microdomains are ordered regions on the plasma membrane of cells, rich in cholesterol and sphingolipids, ranging in size from 10 to 200 nm in diameter. These lipid-ordered domains may serve as platforms to facilitate colocalization of intracellular signaling proteins during agonist-induced signal transduction. It is hypothesized that fish oil will disrupt the lipid microdomains, increasing spatial distribution of these lipid-ordered domains and lateral mobility of the prostaglandin (PG) F2α (FP) receptors in bovine luteal cells...
August 12, 2016: Domestic Animal Endocrinology
Wenchang Zhang, Lianqing Zhu, Fan Zhang, Xiaoping Lou, Chao Liu, Xiaochen Meng
Precision in flow cytometry depends on many factors, the first of which is accurate and stable positioning of the hydrodynamically focused cells. However, no method exists to evaluate the stability of laminar flow and single-cell flow in the flow chamber of the flow cytometer directly because of the small size of the rectangular channel of the flow chamber. In this paper, a method of high-speed particle image velocimetry is proposed to solve this problem. The velocity stability of the particles in the flow chamber is used to evaluate the flow stability of the fluid path of the flow cytometer...
September 15, 2016: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
George R Dakwar, Kevin Braeckmans, Wim Ceelen, Stefaan C De Smedt, Katrien Remaut
Delivery of small interfering RNA (siRNA) is recently gaining tremendous attention for the treatment of ovarian cancer. The present study investigated the potential of different liposomal formulations composed of (2,3-dioleoyloxy-propyl)-trimethylammonium (DOTAP) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) encapsulating siRNA (hydration method) for their ability to knockdown luciferase (Luc) activity in human ovarian cancer SKOV-3 cells. Fluorescence single particle tracking (fSPT) and fluorescence correlation spectroscopy (FCS) in human-undiluted ascites fluid obtained from a peritoneal carcinomatosis patient revealed that cationic hydra-lipoplexes (HYDRA-LPXs) and HYDRA-LPXs decorated with stable DSPE-PEG (DSPE HYDRA-LPXs) showed high stability during at least 24 h...
September 8, 2016: Drug Delivery and Translational Research
Weina Liu, Boris Naydenov, Sabyasachi Chakrabortty, Bettina Wuensch, Kristina Hübner, Sandra Ritz, Helmut Cölfen, Holger Barth, Kaloian Koynov, Haoyuan Qi, Robert Leiter, Rolf Reuter, Jörg Wrachtrup, Felix Boldt, Jonas Scheuer, Ute Kaiser, Miguel Sison, Theo Lasser, Philip Tinnefeld, Fedor Jelezko, Paul Walther, Yuzhou Wu, Tanja Weil
There is a continuous demand for imaging probes offering excellent performance in various microscopy techniques for comprehensive investigations of cellular processes by more than one technique. Fluorescent nanodiamond-gold nanoparticles (FND-Au) constitute a new class of "all-in-one" hybrid particles providing unique features for multimodal cellular imaging including optical imaging, electron microscopy, and, and potentially even quantum sensing. Confocal and optical coherence microscopy of the FND-Au allow fast investigations inside living cells via emission, scattering, and photothermal imaging techniques because the FND emission is not quenched by AuNPs...
October 12, 2016: Nano Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"