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Andriy Chmyrov, Marcel Leutenegger, Tim Grotjohann, Andreas Schönle, Jan Keller-Findeisen, Lars Kastrup, Stefan Jakobs, Gerald Donnert, Steffen J Sahl, Stefan W Hell
Fluorescence microscopy is rapidly turning into nanoscopy. Among the various nanoscopy methods, the STED/RESOLFT super-resolution family has recently been expanded to image even large fields of view within a few seconds. This advance relies on using light patterns featuring substantial arrays of intensity minima for discerning features by switching their fluorophores between 'on' and 'off' states of fluorescence. Here we show that splitting the light with a grating and recombining it in the focal plane of the objective lens renders arrays of minima with wavelength-independent periodicity...
March 20, 2017: Scientific Reports
Gyouil Jeong, Boogeon Choi, Deok-Soo Kim, Seongjin Ahn, Baekwon Park, Jin Hyoun Kang, Hongki Min, Byung Hee Hong, Zee Hwan Kim
Bilayer graphene (BLG) shows great potential as a new material for opto-electronic devices because its bandgap can be controlled by varying the stacking orders, as well as by applying an external electric field. An imaging technique that can visualize and characterize various stacking domains in BLG may greatly help in fully utilizing such properties of BLG. Here we demonstrate that infrared (IR) scattering-type scanning near-field optical microscopy (sSNOM) can visualize Bernal and non-Bernal stacking domains of BLG, based on the stacking-specific inter- and intra-band optical conductivities...
March 13, 2017: Nanoscale
Joanna Oracz, Karl Adolfsson, Volker Westphal, Czeslaw Radzewicz, Magnus T Borgstrom, Steffen Sahl, Christelle Prinz, Stefan W Hell
Nanowires hold great promise as tools for probing and interacting with various molecular and biological systems. Their unique geometrical properties (typically <100 nm in diameter and a few µm in length) enable minimally invasive interactions with living cells, so that electrical signals or forces can be monitored. All such experiments require in situ high-resolution imaging to provide context. While there is a clear need to extend visualization capabilities to the nanoscale, no suitable super-resolution far-field photoluminescence microscopy of extended semiconductor emitters has been described...
March 6, 2017: Nano Letters
Hans Blom, Jerker Widengren
Despite its short history, diffraction-unlimited fluorescence microscopy techniques have already made a substantial imprint in the biological sciences. In this review, we describe how stimulated emission depletion (STED) imaging originally evolved, how it compares to other optical super-resolution imaging techniques, and what advantages it provides compared to previous golden-standards for biological microscopy, such as diffraction-limited optical microscopy and electron microscopy. We outline the prerequisites for successful STED imaging experiments, emphasizing the equally critical roles of instrumentation, sample preparation, and photophysics, and describe major evolving strategies for how to push the borders of STED imaging even further in life science...
March 6, 2017: Chemical Reviews
Patricia Bondia, Rocío Jurado, Santiago Casado, José M Domínguez-Vera, Natividad Gálvez, Cristina Flors
The combination of complementary techniques to characterize materials at the nanoscale is crucial to gain a more complete picture of their structure, a key step to design and fabricate new materials with improved properties and diverse functions. Here it is shown that correlative atomic force microscopy (AFM) and localization-based super-resolution microscopy is a useful tool that provides insight into the structure and emissive properties of fluorescent β-lactoglobulin (βLG) amyloid-like fibrils. These hybrid materials are made by functionalization of βLG with organic fluorophores and quantum dots, the latter being relevant for the production of 1D inorganic nanostructures templated by self-assembling peptides...
March 3, 2017: Small
Xiaowei Liu, Cuifang Kuang, Xiang Hao, Chenlei Pang, Pengfei Xu, Haifeng Li, Ying Liu, Chao Yu, Yingke Xu, Di Nan, Weidong Shen, Yue Fang, Lenian He, Xu Liu, Qing Yang
Here we demonstrate an active method which pioneers in utilizing a combination of a spatial frequency shift and a Stokes frequency shift to enable wide-field far-field subdiffraction imaging. A fluorescent nanowire ring acts as a localized source and is combined with a film waveguide to produce omnidirectional illuminating evanescent waves. Benefitting from the high wave vector of illumination, the high spatial frequencies of an object can be shifted to the passband of a conventional imaging system, contributing subwavelength spatial information to the far-field image...
February 17, 2017: Physical Review Letters
Yujia Liu, Yiqing Lu, Xusan Yang, Xianlin Zheng, Shihui Wen, Fan Wang, Xavier Vidal, Jiangbo Zhao, Deming Liu, Zhiguang Zhou, Chenshuo Ma, Jiajia Zhou, James A Piper, Peng Xi, Dayong Jin
Lanthanide-doped glasses and crystals are attractive for laser applications because the metastable energy levels of the trivalent lanthanide ions facilitate the establishment of population inversion and amplified stimulated emission at relatively low pump power. At the nanometre scale, lanthanide-doped upconversion nanoparticles (UCNPs) can now be made with precisely controlled phase, dimension and doping level. When excited in the near-infrared, these UCNPs emit stable, bright visible luminescence at a variety of selectable wavelengths, with single-nanoparticle sensitivity, which makes them suitable for advanced luminescence microscopy applications...
February 22, 2017: Nature
Peng Gao, G Ulrich Nienhaus
Low-resolution background in stimulated emission depletion (STED) nanoscopy can arise from incomplete depletion or re-excitation by the STED beam. We have recently introduced stimulated emission double depletion (STEDD), a technique to efficiently suppress this background. In STEDD, the conventional, doughnut-shaped STED pulse, which depletes excited fluorophores outside the center of the focal region, is followed by a second Gaussian STED pulse, which specifically depletes the central region. The background is removed by calculating a weighted difference of photon events collected before and after the second STED pulse...
February 15, 2017: Optics Letters
Fabian Göttfert, Tino Pleiner, Jörn Heine, Volker Westphal, Dirk Görlich, Steffen J Sahl, Stefan W Hell
Photobleaching remains a limiting factor in superresolution fluorescence microscopy. This is particularly true for stimulated emission depletion (STED) and reversible saturable/switchable optical fluorescence transitions (RESOLFT) microscopy, where adjacent fluorescent molecules are distinguished by sequentially turning them off (or on) using a pattern of light formed as a doughnut or a standing wave. In sample regions where the pattern intensity reaches or exceeds a certain threshold, the molecules are essentially off (or on), whereas in areas where the intensity is lower, that is, around the intensity minima, the molecules remain in the initial state...
February 28, 2017: Proceedings of the National Academy of Sciences of the United States of America
Jie Xiao, Taekjip Ha
No abstract text is available yet for this article.
February 10, 2017: Science
A Gozar, N E Litombe, Jennifer E Hoffman, I Božović
Helium ion beams (HIB) focused to subnanometer scales have emerged as powerful tools for high-resolution imaging as well as nanoscale lithography, ion milling, or deposition. Quantifying irradiation effects is an essential step toward reliable device fabrication, but most of the depth profiling information is provided by computer simulations rather than the experiment. Here, we demonstrate the use of atomic force microscopy (AFM) combined with scanning near-field optical microscopy (SNOM) to provide three-dimensional (3D) dielectric characterization of high-temperature superconductor devices fabricated by HIB...
March 8, 2017: Nano Letters
Anna L Peters, Cornelis J F van Noorden
Cytochemistry is the discipline that is applied to visualize specific molecules in individual cells and has become an essential tool in life sciences. Immunocytochemistry was developed in the sixties of last century and is the most frequently used cytochemical application. However, metabolic mapping is the oldest cytochemical approach to localize activity of specific enzymes, but in the last decades of the previous century and the first decade of the present century it almost became obsolete. The popularity of this approach revived in the past few years...
2017: Methods in Molecular Biology
Judith Reindl, Stefanie Girst, Dietrich W M Walsh, Christoph Greubel, Benjamin Schwarz, Christian Siebenwirth, Guido A Drexler, Anna A Friedl, Günther Dollinger
The spatial distribution of DSB repair factors γH2AX, 53BP1 and Rad51 in ionizing radiation induced foci (IRIF) in HeLa cells using super resolution STED nanoscopy after low and high linear energy transfer (LET) irradiation was investigated. 53BP1 and γH2AX form IRIF with same mean size of (540 ± 40) nm after high LET irradiation while the size after low LET irradiation is significantly smaller. The IRIF of both repair factors show nanostructures with partial anti-correlation. These structures are related to domains formed within the chromatin territories marked by γH2AX while 53BP1 is mainly situated in the perichromatin region...
January 17, 2017: Scientific Reports
Alison R Dun, Gabriel J Lord, Rhodri S Wilson, Deirdre M Kavanagh, Katarzyna I Cialowicz, Shuzo Sugita, Seungmee Park, Lei Yang, Annya M Smyth, Andreas Papadopulos, Colin Rickman, Rory R Duncan
Eukaryotic plasma membrane organization theory has long been controversial, in part due to a dearth of suitably high-resolution techniques to probe molecular architecture in situ and integrate information from diverse data streams [1]. Notably, clustered patterning of membrane proteins is a commonly conserved feature across diverse protein families (reviewed in [2]), including the SNAREs [3], SM proteins [4, 5], ion channels [6, 7], and receptors (e.g., [8]). Much effort has gone into analyzing the behavior of secretory organelles [9-13], and understanding the relationship between the membrane and proximal organelles [4, 5, 12, 14] is an essential goal for cell biology as broad concepts or rules may be established...
February 6, 2017: Current Biology: CB
Yves F Dufrêne
Studying the structure, properties, and interactions of microbial cells is key to understanding the functions of the microbiome. Recent advances in nanotechnology have offered new tools to probe microbes at the single-molecule and single-cell levels. In this issue of ACS Nano, Kumar et al. present an atomic force microscopy method that is capable of imaging the nanoscale organization of bacterial proteins in native, curved membranes. This study represents an important step forward in the development of nanoscopy techniques for analyzing biological systems with large curvature and vertical dimensions, such as membrane vesicles and bacterial cells...
January 12, 2017: ACS Nano
Mario Raab, Carolin Vietz, Fernando Daniel Stefani, Guillermo Pedro Acuna, Philip Tinnefeld
Over the last decade, two fields have dominated the attention of sub-diffraction photonics research: plasmonics and fluorescence nanoscopy. Nanoscopy based on single-molecule localization offers a practical way to explore plasmonic interactions with nanometre resolution. However, this seemingly straightforward technique may retrieve false positional information. Here, we make use of the DNA origami technique to both control a nanometric separation between emitters and a gold nanoparticle, and as a platform for super-resolution imaging based on single-molecule localization...
January 11, 2017: Nature Communications
Joseph J Kim, Neal K Bennett, Mitchel S Devita, Sanjay Chahar, Satish Viswanath, Eunjee A Lee, Giyoung Jung, Paul P Shao, Erin P Childers, Shichong Liu, Anthony Kulesa, Benjamin A Garcia, Matthew L Becker, Nathaniel S Hwang, Anant Madabhushi, Michael P Verzi, Prabhas V Moghe
While distinct stem cell phenotypes follow global changes in chromatin marks, single-cell chromatin technologies are unable to resolve or predict stem cell fates. We propose the first such use of optical high content nanoscopy of histone epigenetic marks (epi-marks) in stem cells to classify emergent cell states. By combining nanoscopy with epi-mark textural image informatics, we developed a novel approach, termed EDICTS (Epi-mark Descriptor Imaging of Cell Transitional States), to discern chromatin organizational changes, demarcate lineage gradations across a range of stem cell types and robustly track lineage restriction kinetics...
January 4, 2017: Scientific Reports
Gabriela Matela, Peng Gao, Gernot Guigas, Antonia F Eckert, Karin Nienhaus, G Ulrich Nienhaus
Here we present mGarnet2, a monomeric, far-red fluorescent marker protein derived from mRuby, with absorption and emission bands peaking at 598 and 671 nm, respectively. The protein shows excellent performance as a live-cell fusion marker for STED nanoscopy with 640 nm excitation and 780 nm depletion wavelengths.
January 10, 2017: Chemical Communications: Chem Comm
Federico M Barabas, Luciano A Masullo, Fernando D Stefani
Until recently, PC control and synchronization of scientific instruments was only possible through closed-source expensive frameworks like National Instruments' LabVIEW. Nowadays, efficient cost-free alternatives are available in the context of a continuously growing community of open-source software developers. Here, we report on Tormenta, a modular open-source software for the control of camera-based optical microscopes. Tormenta is built on Python, works on multiple operating systems, and includes some key features for fluorescence nanoscopy based on single molecule localization...
December 2016: Review of Scientific Instruments
Robin Diekmann, Deanna L Wolfson, Christoph Spahn, Mike Heilemann, Mark Schüttpelz, Thomas Huser
Imaging non-adherent cells by super-resolution far-field fluorescence microscopy is currently not possible because of their rapid movement while in suspension. Holographic optical tweezers (HOTs) enable the ability to freely control the number and position of optical traps, thus facilitating the unrestricted manipulation of cells in a volume around the focal plane. Here we show that immobilizing non-adherent cells by optical tweezers is sufficient to achieve optical resolution well below the diffraction limit using localization microscopy...
December 13, 2016: Nature Communications
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