scholarly journals Visualization of mt nucleoids by superresolution microscopy techniques

2012 ◽  
Vol 1817 ◽  
pp. S154-S155
Author(s):  
Andrea Dlasková ◽  
Mike Mlodzianoski ◽  
Tomáš Špacek ◽  
Jitka Šantorová ◽  
Jan Tauber ◽  
...  
Keyword(s):  
Superresolution Microscopy ◽  
Microscopy Techniques

Imaging the invisible: resolving cellular microcompartments by superresolution microscopy techniques

2013 ◽  
Vol 394 (9) ◽  
pp. 1097-1113 ◽  
Author(s):  
Michael Hensel ◽  
Jürgen Klingauf ◽  
Jacob Piehler
Keyword(s):  
Imaging Techniques ◽  
Live Cell ◽  
Temporal Organization ◽  
Membrane Microdomains ◽  
Superresolution Microscopy ◽  
Neuronal Synapses ◽  
Spatio Temporal ◽  
Microscopy Techniques ◽  
Plasma Membrane Microdomains ◽  
Diffraction Barrier

Abstract Unraveling the spatio-temporal organization of dynamic cellular microcompartments requires live cell imaging techniques capable of resolving submicroscopic structures. While the resolution of traditional far-field fluorescence imaging techniques is limited by the diffraction barrier, several fluorescence-based microscopy techniques providing sub-100 nm resolution have become available during the past decade. Here, we briefly introduce the optical principles of these techniques and compare their capabilities and limitations with respect to spatial and temporal resolution as well as live cell capabilities. Moreover, we summarize how these techniques contributed to a better understanding of plasma membrane microdomains, the dynamic nanoscale organization of neuronal synapses and the sub-compartmentation of microorganisms. Based on these applications, we highlight complementarity of these techniques and their potential to address specific challenges in the context of dynamic cellular microcompartments, as well as the perspectives to overcome current limitations of these methods.

scholarly journals Profilin connects actin assembly with microtubule dynamics

2016 ◽  
Vol 27 (15) ◽  
pp. 2381-2393 ◽  
Author(s):  
Michaela Nejedla ◽  
Sara Sadi ◽  
Vadym Sulimenko ◽  
Francisca Nunes de Almeida ◽  
Hans Blom ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Actin Dynamics ◽  
Control Element ◽  
Actin Assembly ◽  
Actin Nucleation ◽  
Superresolution Microscopy ◽  
Drug Treatments ◽  
And Migration ◽  
Wasp Family Proteins ◽  
Microscopy Techniques

Profilin controls actin nucleation and assembly processes in eukaryotic cells. Actin nucleation and elongation promoting factors (NEPFs) such as Ena/VASP, formins, and WASP-family proteins recruit profilin:actin for filament formation. Some of these are found to be microtubule associated, making actin polymerization from microtubule-associated platforms possible. Microtubules are implicated in focal adhesion turnover, cell polarity establishment, and migration, illustrating the coupling between actin and microtubule systems. Here we demonstrate that profilin is functionally linked to microtubules with formins and point to formins as major mediators of this association. To reach this conclusion, we combined different fluorescence microscopy techniques, including superresolution microscopy, with siRNA modulation of profilin expression and drug treatments to interfere with actin dynamics. Our studies show that profilin dynamically associates with microtubules and this fraction of profilin contributes to balance actin assembly during homeostatic cell growth and affects micro­tubule dynamics. Hence profilin functions as a regulator of microtubule (+)-end turnover in addition to being an actin control element.

scholarly journals Active and inactive β1 integrins segregate into distinct nanoclusters in focal adhesions

2018 ◽  
Vol 217 (6) ◽  
pp. 1929-1940 ◽  
Author(s):  
Matthias Spiess ◽  
Pablo Hernandez-Varas ◽  
Anna Oddone ◽  
Helene Olofsson ◽  
Hans Blom ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Focal Adhesions ◽  
Stimulated Emission ◽  
Superresolution Microscopy ◽  
Cell Matrix ◽  
Stochastic Optical Reconstruction Microscopy ◽  
Β1 Integrins ◽  
Activity State ◽  
Optical Reconstruction ◽  
Microscopy Techniques

Integrins are the core constituents of cell–matrix adhesion complexes such as focal adhesions (FAs) and play key roles in physiology and disease. Integrins fluctuate between active and inactive conformations, yet whether the activity state influences the spatial organization of integrins within FAs has remained unclear. In this study, we address this question and also ask whether integrin activity may be regulated either independently for each integrin molecule or through locally coordinated mechanisms. We used two distinct superresolution microscopy techniques, stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion microscopy (STED), to visualize active versus inactive β1 integrins. We first reveal a spatial hierarchy of integrin organization with integrin molecules arranged in nanoclusters, which align to form linear substructures that in turn build FAs. Remarkably, within FAs, active and inactive β1 integrins segregate into distinct nanoclusters, with active integrin nanoclusters being more organized. This unexpected segregation indicates synchronization of integrin activities within nanoclusters, implying the existence of a coordinate mechanism of integrin activity regulation.

Membrane Protein Clusters at Nanoscale Resolution: More Than Pretty Pictures

Physiology ◽  
2010 ◽  
Vol 25 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Thorsten Lang ◽  
Silvio O. Rizzoli
Keyword(s):  
Membrane Protein ◽  
Fluorescence Microscopy ◽  
Molecular Machines ◽  
Protein Conformations ◽  
Superresolution Microscopy ◽  
Protein Clusters ◽  
Microscopy Techniques

Fluorescence microscopy is powerful for analyzing the composition and dynamics of cellular elements, but studying precise molecule patterns is precluded due to diffraction limited resolution. This barrier has been lifted now through several superresolution microscopy techniques. They revealed that proteins assemble in defined groups (clusters). A new challenge thus appears for the biologist: to find out whether clusters are molecular machines, stabilizers of defined protein conformations, or simply protein reservoirs.

scholarly journals Modular transient nanoclustering of activated β2-adrenergic receptors revealed by single-molecule tracking of conformation-specific nanobodies

2020 ◽  
Vol 117 (48) ◽  
pp. 30476-30487 ◽  
Author(s):  
Rachel S. Gormal ◽  
Pranesh Padmanabhan ◽  
Ravikiran Kasula ◽  
Adekunle T. Bademosi ◽  
Sean Coakley ◽  
...  
Keyword(s):  
Single Molecule ◽  
Neurosecretory Cells ◽  
Single Particle Tracking ◽  
Single Domain ◽  
Live Cells ◽  
Conformational States ◽  
Superresolution Microscopy ◽  
Endogenous Protein ◽  
Endogenous Proteins ◽  
Microscopy Techniques

None of the current superresolution microscopy techniques can reliably image the changes in endogenous protein nanoclustering dynamics associated with specific conformations in live cells. Single-domain nanobodies have been invaluable tools to isolate defined conformational states of proteins, and we reasoned that expressing these nanobodies coupled to single-molecule imaging-amenable tags could allow superresolution analysis of endogenous proteins in discrete conformational states. Here, we used anti-GFP nanobodies tagged with photoconvertible mEos expressed as intrabodies, as a proof-of-concept to perform single-particle tracking on a range of GFP proteins expressed in live cells, neurons, and small organisms. We next expressed highly specialized nanobodies that target conformation-specific endogenous β2-adrenoreceptor (β2-AR) in neurosecretory cells, unveiling real-time mobility behaviors of activated and inactivated endogenous conformers during agonist treatment in living cells. We showed that activated β2-AR(Nb80) is highly immobile and organized in nanoclusters. The Gαs−GPCR complex detected with Nb37 displayed higher mobility with surprisingly similar nanoclustering dynamics to that of Nb80. Activated conformers are highly sensitive to dynamin inhibition, suggesting selective targeting for endocytosis. Inactivated β2-AR(Nb60) molecules are also largely immobile but relatively less sensitive to endocytic blockade. Expression of single-domain nanobodies therefore provides a unique opportunity to capture highly transient changes in the dynamic nanoscale organization of endogenous proteins.

A SEM/TEM examination of a ceramic membrane

1986 ◽  
Vol 44 ◽  
pp. 682-683
Author(s):  
C.E. Voegele-Kliewer ◽  
A.D. McMaster ◽  
G.W. Dirks
Keyword(s):  
Electron Microscopy ◽  
Gas Separation ◽  
Ceramic Membrane ◽  
Hydrogen Iodide ◽  
Separation Processes ◽  
Corning Glass ◽  
Gas Transport Properties ◽  
Porous Microstructure ◽  
Microscopy Techniques ◽  
The Relationship

Materials other than polymers, e.g. ceramic silicates, are currently being investigated for gas separation processes. The permeation characteristics of one such material, Vycor (Corning Glass #1370), have been reported for the separation of hydrogen from hydrogen iodide. This paper will describe the electron microscopy techniques applied to reveal the porous microstructure of a Vycor membrane. The application of these techniques has led to an increased understanding in the relationship between the substructure and the gas transport properties of this material.

Acoustic microscopy techniques for the inspection of integrated circuit devices and packages

1992 ◽  
Vol 50 (2) ◽  
pp. 966-967
Author(s):  
Thomas M. Moore
Keyword(s):  
Integrated Circuit ◽  
Acoustic Microscopy ◽  
Hybrid Technique ◽  
Frequency Scanning ◽  
Ic Packaging ◽  
Ic Package ◽  
Microscopy Techniques ◽  
Ic Package Inspection ◽  
Pulse Echo ◽  
Scanning Acoustic Microscope

In the last decade, a variety of characterization techniques based on acoustic phenomena have come into widespread use. Characteristics of matter waves such as their ability to penetrate optically opaque solids and produce image contrast based on acoustic impedance differences have made these techniques attractive to semiconductor and integrated circuit (IC) packaging researchers.These techniques can be divided into two groups. The first group includes techniques primarily applied to IC package inspection which take advantage of the ability of ultrasound to penetrate deeply and nondestructively through optically opaque solids. C-mode Acoustic Microscopy (C-AM) is a recently developed hybrid technique which combines the narrow-band pulse-echo piezotransducers of conventional C-scan recording with the precision scanning and sophisticated signal analysis capabilities normally associated with the high frequency Scanning Acoustic Microscope (SAM). A single piezotransducer is scanned over the sample and both transmits acoustic pulses into the sample and receives acoustic echo signals from the sample.

Etching of LLDPE and LLDPE/HDPE blends

1996 ◽  
Vol 54 ◽  
pp. 200-201
Author(s):  
M. S. Bischel ◽  
J. M. Schultz
Keyword(s):  
Potassium Permanganate ◽  
Morphological Features ◽  
Narrow Fraction ◽  
Potassium Permanganate Solution ◽  
Commercial Applications ◽  
Microscopy Techniques

Despite its rapidly growing use in commercial applications, the morphology of LLDPE and its blends has not been thoroughly studied by microscopy techniques. As part of a study to examine the morphology of a LLDPE narrow fraction and its blends with HDPE via SEM, TEM and AFM, an appropriate etchant is required. However, no satisfactory recipes could be found in the literature. Mirabella used n-heptane, a solvent for LLDPE, as an etchant to reveal certain morphological features in the SEM, including faint banding in spherulites. A 1992 paper by Bassett included a TEM micrograph of an axialite of LLDPE, etched in a potassium permanganate solution, but no details were given.Attempts to use n-heptane, at 60°C, as an etchant were unsuccessful: depending upon thickness, samples swelled and increased in diameter by 5-10% or more within 15 minutes. Attempts to use the standard 3.5% potassium permanganate solution for HDPE were also unsuccessful: the LLDPE was severely overetched. Weaker solutions were also too severe.

Case Study: Combined Dynamic Laser Stimulation and Static Emission Microscopy Techniques Applied to Scan Test Failure on Mixed Mode Device

2012 ◽  
Author(s):  
Magdalena Sienkiewicz ◽  
Philippe Rousseille
Keyword(s):  
Mixed Mode ◽  
Laser Stimulation ◽  
Scan Test ◽  
Silicon Bulk ◽  
Defect Localization ◽  
Emission Microscopy ◽  
Microscopy Techniques ◽  
Test Failure

Abstract This paper presents a case study on scan test reject in a mixed mode IC. It focuses on the smart use of combined mature FA techniques, such as Soft Defect Localization (SDL) and emission microscopy (EMMI), to localize a random scan test anomaly at the silicon bulk level.

Case Study in Fault Isolation of a Metal Short for Yield Enhancement

2010 ◽  
Author(s):  
Sarven Ipek ◽  
David Grosjean
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Photon Emission ◽  
Fault Isolation ◽  
Yield Enhancement ◽  
Analysis Technique ◽  
Laser Signal ◽  
Signal Injection ◽  
Microscopy Techniques

Abstract The application of an individual failure analysis technique rarely provides the failure mechanism. More typically, the results of numerous techniques need to be combined and considered to locate and verify the correct failure mechanism. This paper describes a particular case in which different microscopy techniques (photon emission, laser signal injection, and current imaging) gave clues to the problem, which then needed to be combined with manual probing and a thorough understanding of the circuit to locate the defect. By combining probing of that circuit block with the mapping and emission results, the authors were able to understand the photon emission spots and the laser signal injection microscopy (LSIM) signatures to be effects of the defect. It also helped them narrow down the search for the defect so that LSIM on a small part of the circuit could lead to the actual defect.

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