201
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Hohlbein J, Gryte K, Heilemann M, Kapanidis AN. Surfing on a new wave of single-molecule fluorescence methods. Phys Biol 2010; 7:031001. [DOI: 10.1088/1478-3975/7/3/031001] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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202
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Lang T, Rizzoli SO. Membrane protein clusters at nanoscale resolution: more than pretty pictures. Physiology (Bethesda) 2010; 25:116-24. [PMID: 20430955 DOI: 10.1152/physiol.00044.2009] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
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.
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Affiliation(s)
- Thorsten Lang
- LIMES-Institute, Laboratory of Membrane Biochemistry, University of Bonn, Bonn
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203
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Schermelleh L, Heintzmann R, Leonhardt H. A guide to super-resolution fluorescence microscopy. ACTA ACUST UNITED AC 2010; 190:165-75. [PMID: 20643879 PMCID: PMC2918923 DOI: 10.1083/jcb.201002018] [Citation(s) in RCA: 791] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For centuries, cell biology has been based on light microscopy and at the same time been limited by its optical resolution. However, several new technologies have been developed recently that bypass this limit. These new super-resolution technologies are either based on tailored illumination, nonlinear fluorophore responses, or the precise localization of single molecules. Overall, these new approaches have created unprecedented new possibilities to investigate the structure and function of cells.
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Affiliation(s)
- Lothar Schermelleh
- Department of Biology and Center for Integrated Protein Science, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany.
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204
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205
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Kasper R, Harke B, Forthmann C, Tinnefeld P, Hell SW, Sauer M. Single-molecule STED microscopy with photostable organic fluorophores. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:1379-1384. [PMID: 20521266 DOI: 10.1002/smll.201000203] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- Robert Kasper
- Applied Laser Physics and Laser Spectroscopy Bielefeld University Universitätsstr. 25, 33615 Bielefeld, Germany
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206
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Rouquette J, Cremer C, Cremer T, Fakan S. Functional nuclear architecture studied by microscopy: present and future. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 282:1-90. [PMID: 20630466 DOI: 10.1016/s1937-6448(10)82001-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this review we describe major contributions of light and electron microscopic approaches to the present understanding of functional nuclear architecture. The large gap of knowledge, which must still be bridged from the molecular level to the level of higher order structure, is emphasized by differences of currently discussed models of nuclear architecture. Molecular biological tools represent new means for the multicolor visualization of various nuclear components in living cells. New achievements offer the possibility to surpass the resolution limit of conventional light microscopy down to the nanometer scale and require improved bioinformatics tools able to handle the analysis of large amounts of data. In combination with the much higher resolution of electron microscopic methods, including ultrastructural cytochemistry, correlative microscopy of the same cells in their living and fixed state is the approach of choice to combine the advantages of different techniques. This will make possible future analyses of cell type- and species-specific differences of nuclear architecture in more detail and to put different models to critical tests.
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Affiliation(s)
- Jacques Rouquette
- Biocenter, Ludwig Maximilians University (LMU), Martinsried, Germany
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207
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Shariff A, Murphy RF, Rohde GK. A generative model of microtubule distributions, and indirect estimation of its parameters from fluorescence microscopy images. Cytometry A 2010; 77:457-66. [PMID: 20104579 PMCID: PMC2901542 DOI: 10.1002/cyto.a.20854] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The microtubule network plays critical roles in many cellular processes, and quantitative models of how its organization varies across cell types and conditions are required for understanding those roles and as input to cell simulations. High-throughput image acquisition technologies are potentially valuable for this purpose, but do not provide sufficient resolution for current analysis methods that rely on tracing of individual microtubules. We describe a parametric conditional model of microtubule distribution that can generate a microtubule network in intact cells using a persistent random walk approach. The model parameters are physically meaningful as they directly describe the spatial distribution of microtubules and include the number of microtubules as well as the mean of the length distribution. We also present an indirect method for estimating the parameters of the model from three-dimensional fluorescence microscope images of cells that relies on comparing acquired images with simulated images generated from the model. Our results show that our method can reasonably recover parameters for a given query image, and we present the distributions of parameters estimated by our method for a collection of HeLa cell images. (c) 2010 International Society for Advancement of Cytometry.
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Affiliation(s)
- Aabid Shariff
- Lane Center for Computational Biology and Center for Bioimage Informatics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
- Joint Carnegie Mellon University-University of Pittsburgh Ph.D. Program in Computational Biology
| | - Robert F. Murphy
- Lane Center for Computational Biology and Center for Bioimage Informatics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
- Joint Carnegie Mellon University-University of Pittsburgh Ph.D. Program in Computational Biology
- Department of Biomedical Engineering, Carnegie Mellon University
- Departments of Biological Sciences and Machine Learning, Carnegie Mellon University
- External Senior Fellow, Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany
| | - Gustavo K. Rohde
- Lane Center for Computational Biology and Center for Bioimage Informatics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
- Joint Carnegie Mellon University-University of Pittsburgh Ph.D. Program in Computational Biology
- Department of Biomedical Engineering, Carnegie Mellon University
- Department of Electrical and Computer Engineering, Carnegie Mellon University
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208
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Kuang C, Zhao W, Wang G. Far-field optical nanoscopy based on continuous wave laser stimulated emission depletion. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:053709. [PMID: 20515147 DOI: 10.1063/1.3432001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Stimulated emission depletion (STED) microscopy is one of the breakthrough technologies that belong to far-field optical microscopy and can achieve nanoscale spatial resolution. We demonstrate a far-field optical nanoscopy based on continuous wave lasers with different wavelengths, i.e., violet and green lasers for excitation and STED, respectively. Fluorescent dyes Coumarin 102 and Atto 390 are used for validating the depletion efficiency. Fluorescent nanoparticles are selected for characterizing the spatial resolution of the STED system. Linear scanning of the laser beams of the STED system along one line of a microscope slide, which is coated with the nanoparticles, indicates that a spatial resolution of about 70 nm has so far been achieved. A two-dimensional image of the particle pattern of the STED system is constructed and compared with scanning confocal microscope. The present work has further extended the application of the STED microscopy into the blue regime.
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Affiliation(s)
- Cuifang Kuang
- Department of Mechanical Engineering and Biomedical Engineering Program, University of South Carolina, Columbia, South Carolina 29208, USA
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209
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Cebecauer M, Spitaler M, Sergé A, Magee AI. Signalling complexes and clusters: functional advantages and methodological hurdles. J Cell Sci 2010; 123:309-20. [PMID: 20130139 DOI: 10.1242/jcs.061739] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Signalling molecules integrate, codify and transport information in cells. Organisation of these molecules in complexes and clusters improves the efficiency, fidelity and robustness of cellular signalling. Here, we summarise current views on how signalling molecules assemble into macromolecular complexes and clusters and how they use their physical properties to transduce environmental information into a variety of cellular processes. In addition, we discuss recent innovations in live-cell imaging at the sub-micrometer scale and the challenges of object (particle) tracking, both of which help us to observe signalling complexes and clusters and to examine their dynamic character.
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Affiliation(s)
- Marek Cebecauer
- Section of Molecular Medicine, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK.
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210
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A nanometer scale optical view on the compartmentalization of cell membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:777-87. [DOI: 10.1016/j.bbamem.2009.09.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/13/2009] [Accepted: 09/20/2009] [Indexed: 12/30/2022]
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211
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Mitronova GY, Belov VN, Bossi ML, Wurm CA, Meyer L, Medda R, Moneron G, Bretschneider S, Eggeling C, Jakobs S, Hell SW. New fluorinated rhodamines for optical microscopy and nanoscopy. Chemistry 2010; 16:4477-88. [PMID: 20309973 DOI: 10.1002/chem.200903272] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Indexed: 12/17/2022]
Abstract
New photostable rhodamine dyes represented by the compounds 1 a-r and 3-5 are proposed as efficient fluorescent markers with unique combination of structural features. Unlike rhodamines with monoalkylated nitrogen atoms, N',N-bis(2,2,2-trifluoroethyl) derivatives 1 e, 1 i, 1 j, 3-H and 5 were found to undergo sulfonation of the xanthene fragment at the positions 4' and 5'. Two fluorine atoms were introduced into the positions 2' and 7' of the 3',6'-diaminoxanthene fragment in compounds 1 a-d, 1 i-l and 1 m-r. The new rhodamine dyes may be excited with λ=488 or 514 nm light; most of them emit light at λ=512-554 nm (compounds 1 q and 1r at λ=576 and 589 nm in methanol, respectively) and have high fluorescence quantum yields in solution (up to 98 %), relatively long excited-state lifetimes (>3 ns) and are resistant against photobleaching, especially at high laser intensities, as is usually applied in confocal microscopy. Sulfonation of the xanthene fragment with 30 % SO3 in H2SO4 is compatible with the secondary amide bond (rhodamine-CON(Me)CH2CH2COOH) formed with MeNHCH2CH2COOCH3 to providing the sterically unhindered carboxylic group required for further (bio)conjugation reactions. After creating the amino reactive sites, the modified derivatives may be used as fluorescent markers and labels for (bio)molecules in optical microscopy and nanoscopy with very-high light intensities. Further, the new rhodamine dyes are able to pass the plasma membrane of living cells, introducing them as potential labels for recent live-cell-tag approaches. We exemplify the excellent performance of the fluorinated rhodamines in optical microscopy by fluorescence correlation spectroscopy (FCS) and stimulated emission depletion (STED) nanoscopy experiments.
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Affiliation(s)
- Gyuzel Yu Mitronova
- Department of Nano-Biophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen (Germany), Fax: (+49) 551-2012505
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212
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Hotta JI, Fron E, Dedecker P, Janssen KPF, Li C, Müllen K, Harke B, Bückers J, Hell SW, Hofkens J. Spectroscopic Rationale for Efficient Stimulated-Emission Depletion Microscopy Fluorophores. J Am Chem Soc 2010; 132:5021-3. [DOI: 10.1021/ja100079w] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jun-ichi Hotta
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Eduard Fron
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Peter Dedecker
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Kris P. F. Janssen
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Chen Li
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Klaus Müllen
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Benjamin Harke
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Johanna Bückers
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Stefan W. Hell
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Johan Hofkens
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium, BIOSYST - MeBioS, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Heverlee, Belgium, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, and Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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213
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Opazo F, Punge A, Bückers J, Hoopmann P, Kastrup L, Hell SW, Rizzoli SO. Limited Intermixing of Synaptic Vesicle Components upon Vesicle Recycling. Traffic 2010; 11:800-12. [DOI: 10.1111/j.1600-0854.2010.01058.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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214
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Optically resolving individual microtubules in live axons. Structure 2010; 17:1433-41. [PMID: 19913478 DOI: 10.1016/j.str.2009.09.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 08/21/2009] [Accepted: 09/01/2009] [Indexed: 12/24/2022]
Abstract
Microtubules are essential cytoskeletal tracks for cargo transportation in axons and also serve as the primary structural scaffold of neurons. Structural assembly, stability, and dynamics of axonal microtubules are of great interest for understanding neuronal functions and pathologies. However, microtubules are so densely packed in axons that their separations are well below the diffraction limit of light, which precludes using optical microscopy for live-cell studies. Here, we present a single-molecule imaging method capable of resolving individual microtubules in live axons. In our method, unlabeled microtubules are revealed by following individual axonal cargos that travel along them. We resolved more than six microtubules in a 1 microm diameter axon by real-time tracking of endosomes containing quantum dots. Our live-cell study also provided direct evidence that endosomes switch between microtubules while traveling along axons, which has been proposed to be the primary means for axonal cargos to effectively navigate through the crowded axoplasmic environment.
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215
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Roelfsema MRG, Hedrich R. Making sense out of Ca(2+) signals: their role in regulating stomatal movements. PLANT, CELL & ENVIRONMENT 2010; 33:305-321. [PMID: 19906147 DOI: 10.1111/j.1365-3040.2009.02075.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Plant cells maintain high Ca(2+) concentration gradients between the cytosol and the extracellular matrix, as well as intracellular compartments. During evolution, the regulatory mechanisms, maintaining low cytosolic free Ca(2+) concentrations, most likely provided the backbone for the development of Ca(2+)-dependent signalling pathways. In this review, the current understanding of molecular mechanisms involved in Ca(2+) homeostasis of plants cells is evaluated. The question is addressed to which extent the mechanisms, controlling the cytosolic Ca(2+) concentration, are linked to Ca(2+)-based signalling. A large number of environmental stimuli can evoke Ca(2+) signals, but the Ca(2+)-induced responses are likely to differ depending on the stimulus applied. Two mechanisms are put forward to explain signal specificity of Ca(2+)-dependent responses. A signal may evoke a specific Ca(2+) signature that is recognized by downstream signalling components. Alternatively, Ca(2+) signals are accompanied by Ca(2+)-independent signalling events that determine the specificity of the response. The existence of such parallel-acting pathways explains why guard cell responses to abscisic acid (ABA) can occur in the absence, as well as in the presence, of Ca(2+) signals. Future research may shed new light on the relation between parallel acting Ca(2+)-dependent and -independent events, and may provide insights in their evolutionary origin.
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Affiliation(s)
- M Rob G Roelfsema
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany.
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216
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Humpolícková J, Benda A, Enderlein J. Optical saturation as a versatile tool to enhance resolution in confocal microscopy. Biophys J 2010; 97:2623-9. [PMID: 19883606 DOI: 10.1016/j.bpj.2009.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/16/2009] [Accepted: 08/03/2009] [Indexed: 11/15/2022] Open
Abstract
One of the most actively developing areas in fluorescence microscopy is the achievement of spatial resolution below Abbe's diffraction limit, which restricts the resolution to several hundreds of nanometers. Most of the approaches in use at this time require a complex optical setup, a difficult mathematical treatment, or usage of dyes with special photophysical properties. In this work, we present a new, to our knowledge, approach in confocal microscopy that enhances the resolution moderately but is both technically and computationally simple. As it is based on the saturation of the transition from the ground state to the first excited state, it is universally applicable with respect to the dye used. The idea of the method presented is based on a principle similar to that underlying saturation excitation microscopy, but instead of applying harmonically modulated excitation light, the fluorophores are excited by picosecond laser pulses at different intensities, resulting in different levels of saturation. We show that the method can be easily combined with the concept of triplet relaxation, which by tuning the dark periods between pulses helps to suppress the formation of a photolabile triplet state and effectively reduces photobleaching. We demonstrate our approach imaging GFP-labeled protein patches within the plasma membrane of yeast cells.
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Affiliation(s)
- Jana Humpolícková
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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217
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Neu TR, Manz B, Volke F, Dynes JJ, Hitchcock AP, Lawrence JR. Advanced imaging techniques for assessment of structure, composition and function in biofilm systems. FEMS Microbiol Ecol 2010; 72:1-21. [PMID: 20180852 DOI: 10.1111/j.1574-6941.2010.00837.x] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Scientific imaging represents an important and accepted research tool for the analysis and understanding of complex natural systems. Apart from traditional microscopic techniques such as light and electron microscopy, new advanced techniques have been established including laser scanning microscopy (LSM), magnetic resonance imaging (MRI) and scanning transmission X-ray microscopy (STXM). These new techniques allow in situ analysis of the structure, composition, processes and dynamics of microbial communities. The three techniques open up quantitative analytical imaging possibilities that were, until a few years ago, impossible. The microscopic techniques represent powerful tools for examination of mixed environmental microbial communities usually encountered in the form of aggregates and films. As a consequence, LSM, MRI and STXM are being used in order to study complex microbial biofilm systems. This mini review provides a short outline of the more recent applications with the intention to stimulate new research and imaging approaches in microbiology.
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Affiliation(s)
- Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany.
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218
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Kuang C, Wang G. A novel far-field nanoscopic velocimetry for nanofluidics. LAB ON A CHIP 2010; 10:240-245. [PMID: 20066253 DOI: 10.1039/b917584a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
For the first time we have been able to measure the flow velocity profile for nanofluidics with a spatial resolution better than 70 nm. Due to the diffraction resolution barrier, traditional optical methods have so far failed in measuring the velocity profile in a nanocapillary or a closed nanochannel without an opened sidewall. A novel optical point measurement method is presented which applies stimulated emission depletion (STED) microscopy to laser induced fluorescence photobleaching anemometer (LIFPA) techniques to measure flow velocity. Herein we demonstrate this far-field nanoscopic velocimetry method by measuring the velocity profile in a nanocapillary with an inner diameter of 360 nm. The closest measuring point to the wall is about 35 nm. This method opens up a new class of functional measuring techniques for nanofluidics and for nanoscale flows from the wall.
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Affiliation(s)
- Cuifang Kuang
- Department of Mechanical Engineering & Biomedical Engineering Program, University of South Carolina, Columbia, SC 29208, USA
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219
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Moneron G, Medda R, Hein B, Giske A, Westphal V, Hell SW. Fast STED microscopy with continuous wave fiber lasers. OPTICS EXPRESS 2010; 18:1302-1309. [PMID: 20173956 DOI: 10.1364/oe.18.001302] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report on fast beam-scanning stimulated-emission-depletion (STED) microscopy in the visible range using for resolution enhancement compact, low cost and turn-key continuous wave (CW) fiber lasers emitting at 592 nm. Spatial resolutions of 35 to 65 nm in the focal plane are shown for various samples including fluorescent nanoparticles, immuno-stained cells with a non-exhaustive selection of 5 commonly used organic fluorescent markers, and living cells expressing the yellow fluorescent protein Citrine. The potential of the straightforward combination of CW-STED and fast beam scanning is illustrated in a movie of the endoplasmic reticulum (ER) of a living cell, composed of 100 frames (6 microm x 12 microm), each of them acquired in a time shorter than 0.2 s.
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Affiliation(s)
- Gael Moneron
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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220
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Reuss M, Engelhardt J, Hell SW. Birefringent device converts a standard scanning microscope into a STED microscope that also maps molecular orientation. OPTICS EXPRESS 2010; 18:1049-1058. [PMID: 20173926 DOI: 10.1364/oe.18.001049] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Stimulated emission depletion (STED) microscopy usually employs a scanning excitation beam that is superimposed by a donut-shaped STED beam for keeping the fluorophores at the periphery of the excitation spot dark. Here, we introduce a simple birefringent device that produces a donut-shaped focal spot with suitable polarization for STED, while leaving the excitation spot virtually intact. The device instantly converts a scanning (confocal) microscope with a co-aligned STED beam into a full-blown STED microscope. The donut can be adapted to reveal, through the resulting fluorescence image, the orientation of fluorophores in the sample, thus directly providing subdiffraction resolution images of molecular orientation.
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Affiliation(s)
- Matthias Reuss
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Heidelberg, Germany
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222
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Abstract
Since the discovery of the diffraction barrier in the late nineteenth century, it has been commonly accepted that with far-field optical microscopy it is not possible to resolve structural details considerably finer than half the wavelength of light. The emergence of STED microscopy showed that, at least for fluorescence imaging, these limits can be overcome. Since STED microscopy is a far-field technique, in principle, the same sample preparation as for conventional confocal microscopy may be utilized. The increased resolution, however, requires additional precautions to ensure the structural preservation of the specimen. We present robust protocols to generate test samples for STED microscopy. These protocols for bead samples and immunolabeled mammalian cells may be used as starting points to adapt existing labeling strategies for the requirements of sub-diffraction resolution microscopy.
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223
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Size-Minimized Quantum Dots for Molecular and Cellular Imaging. SINGLE MOLECULE SPECTROSCOPY IN CHEMISTRY, PHYSICS AND BIOLOGY 2010. [DOI: 10.1007/978-3-642-02597-6_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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224
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225
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Burghardt TP, Hipp AD, Ajtai K. Around-the-objective total internal reflection fluorescence microscopy. APPLIED OPTICS 2009; 48:6120-31. [PMID: 19904308 PMCID: PMC2802224 DOI: 10.1364/ao.48.006120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Total internal reflection fluorescence (TIRF) microscopy uses the evanescent field on the aqueous side of a glass/aqueous interface to selectively illuminate fluorophores within approximately 100 nm of the interface. Applications of the method include epi-illumination TIRF, where the exciting light is refracted by the microscope objective to impinge on the interface at incidence angles beyond critical angle, and prism-based TIRF, where exciting light propagates to the interface externally to the microscope optics. The former has higher background autofluorescence from the glass elements of the objective where the exciting beam is focused, and the latter does not collect near-field emission from the fluorescent sample. Around-the-objective TIRF, developed here, creates the evanescent field by conditioning the exciting laser beam to propagate through the submillimeter gap created by the oil immersion high numerical aperture objective and the glass coverslip. The approach eliminates background light due to the admission of the laser excitation to the microscopic optics while collecting near-field emission from the dipoles excited by the approximately 50 nm deep evanescent field.
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Affiliation(s)
- Thomas P Burghardt
- Department of Biochemistry and Molecular Biology, Mayo Clinic Rochester, Rochester, Minnesota 55905, USA.
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226
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Ghafari H, Zhou Y, Ali S, Hanley QS. Confocal detection of planar homogeneous and heterogeneous immunosorbent assays. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:064022. [PMID: 20059260 DOI: 10.1117/1.3268772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Optically sectioned detection of fluorescence immunoassays using a confocal microscope enables the creation of both homo- and heterogeneous planar format assays. We report a set assays requiring optically sectioned detection using a model system and analysis procedures for separating signals of a surface layer from an overlying solution. A model sandwich assay with human immunoglobulin G as the target antigen is created on a glass substrate. The prepared surfaces are exposed to antigen and a FITC-labeled secondary antibody. The resulting preparations are either read directly to provide a homogeneous assay or after wash steps, giving a heterogeneous assay. The simplicity of the object shapes arising from the planar format makes the decomposition of analyte signals from the thin film bound to the surface and overlayer straightforward. Measured response functions of the thin film and overlayer fit well to the Cauchy-Lorentz and cumulative Cauchy-Lorentz functions, respectively, enabling the film and overlayer to be separated. Under the conditions used, the detection limits for the homogeneous and heterogeneous forms of the assay are 2.2 and 5.5 ng/ml, respectively. Planar format, confocally read fluorescence assays enable wash-free detection of antigens and should be applicable to a wide range of assays involving surface-bound species.
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Affiliation(s)
- Homanaz Ghafari
- Nottingham Trent University, School of Science and Technology, Clifton Lane, Nottingham NG11 8NS, United Kingdom
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227
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Cisek R, Spencer L, Prent N, Zigmantas D, Espie GS, Barzda V. Optical microscopy in photosynthesis. PHOTOSYNTHESIS RESEARCH 2009; 102:111-41. [PMID: 19851883 DOI: 10.1007/s11120-009-9500-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 10/05/2009] [Indexed: 05/03/2023]
Abstract
Emerging as well as the most frequently used optical microscopy techniques are reviewed and image contrast generation methods in a microscope are presented, focusing on the nonlinear contrasts such as harmonic generation and multiphoton excitation fluorescence. Nonlinear microscopy presents numerous advantages over linear microscopy techniques including improved deep tissue imaging, optical sectioning, and imaging of live unstained samples. Nonetheless, with the exception of multiphoton excitation fluorescence, nonlinear microscopy is in its infancy, lacking protocols, users and applications; hence, this review focuses on the potential of nonlinear microscopy for studying photosynthetic organisms. Examples of nonlinear microscopic imaging are presented including isolated light-harvesting antenna complexes from higher plants, starch granules, chloroplasts, unicellular alga Chlamydomonas reinhardtii, and cyanobacteria Leptolyngbya sp. and Anabaena sp. While focusing on nonlinear microscopy techniques, second and third harmonic generation and multiphoton excitation fluorescence microscopy, other emerging nonlinear imaging modalities are described and several linear optical microscopy techniques are reviewed in order to clearly describe their capabilities and to highlight the advantages of nonlinear microscopy.
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Affiliation(s)
- Richard Cisek
- Department of Chemical and Physical Sciences, University of Toronto, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
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228
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Wilt BA, Burns LD, Wei Ho ET, Ghosh KK, Mukamel EA, Schnitzer MJ. Advances in light microscopy for neuroscience. Annu Rev Neurosci 2009; 32:435-506. [PMID: 19555292 DOI: 10.1146/annurev.neuro.051508.135540] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Since the work of Golgi and Cajal, light microscopy has remained a key tool for neuroscientists to observe cellular properties. Ongoing advances have enabled new experimental capabilities using light to inspect the nervous system across multiple spatial scales, including ultrastructural scales finer than the optical diffraction limit. Other progress permits functional imaging at faster speeds, at greater depths in brain tissue, and over larger tissue volumes than previously possible. Portable, miniaturized fluorescence microscopes now allow brain imaging in freely behaving mice. Complementary progress on animal preparations has enabled imaging in head-restrained behaving animals, as well as time-lapse microscopy studies in the brains of live subjects. Mouse genetic approaches permit mosaic and inducible fluorescence-labeling strategies, whereas intrinsic contrast mechanisms allow in vivo imaging of animals and humans without use of exogenous markers. This review surveys such advances and highlights emerging capabilities of particular interest to neuroscientists.
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Affiliation(s)
- Brian A Wilt
- James H. Clark Center and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
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229
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Giansante C, Olive AGL, Schäfer C, Raffy G, Del Guerzo A. Time-resolved confocal fluorescence microscopy of trinitrobenzene-responsive organic nanofibers. Anal Bioanal Chem 2009; 396:125-31. [DOI: 10.1007/s00216-009-3179-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 09/09/2009] [Accepted: 09/21/2009] [Indexed: 12/01/2022]
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230
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WILDANGER D, MEDDA R, KASTRUP L, HELL S. A compact STED microscope providing 3D nanoscale resolution. J Microsc 2009; 236:35-43. [DOI: 10.1111/j.1365-2818.2009.03188.x] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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231
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Tychinsky V. The metabolic component of cellular refractivity and its importance for optical cytometry. JOURNAL OF BIOPHOTONICS 2009; 2:494-504. [PMID: 19644930 DOI: 10.1002/jbio.200910042] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Initially, it has been shown that the phase thickness and refractivity (the latter interpreted as the difference of the refractivity indices of an object and surrounding medium) depend on the functional state of mitochondria. The refractivity of various objects decreased in response to energy depletion. This dependence was then demonstrated for other biological objects such as cyanobacteria, chloroplasts and human cells. This general response brought about the hypothesis of a certain "universal" factor that links the variable (or metabolic) component of refractivity with the object's functional state. However, the origin of this phenomenon remains unknown. Our hypothesis is founded on the dependence of polarization of bound water molecules and the activity of metabolic processes. Here, we show the results of measurements of metabolic component of refractivity different bio-objects (mitochondria, chloroplasts, spores, cancer cells) obtained using the Coherent Phase Microscope "Airyscan". Estimations indicated high (up to n approximately = 1.41-1.45) values for the equivalent refractive index of structured water in cells.
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Affiliation(s)
- V Tychinsky
- Moscow State Institute for Radioengineering, Electronics and Automation, prosp. Vernadskogo 78, 119454 Moscow, Russia.
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232
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Wildanger D, Bückers J, Westphal V, Hell SW, Kastrup L. A STED microscope aligned by design. OPTICS EXPRESS 2009; 17:16100-16110. [PMID: 19724610 DOI: 10.1364/oe.17.016100] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
STED microscopes are commonly built using separate optical paths for the excitation and the STED beam. As a result, the beams must be co-aligned and can be subject to mechanical drift. Here, we present a single-path STED microscope whose beams are aligned by design and hence is insensitive to mechanical drift. The design of a phase plate is described which selectively modulates the STED beam but leaves the excitation beam unaffected. The performance of the single-beam setup is on par with previous dual-beam designs.
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Affiliation(s)
- Dominik Wildanger
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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233
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Rankin BR, Hell SW. STED microscopy with a MHz pulsed stimulated-Raman-scattering source. OPTICS EXPRESS 2009; 17:15679-15684. [PMID: 19724567 DOI: 10.1364/oe.17.015679] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We perform stimulated emission depletion (STED) microscopy with a novel light source consisting of a fiber-amplified, frequency doubled laser operating with a 1 MHz repetition rate and a 530 nm output coupled into a standard single mode fiber to produce a tunable spectrum of discrete peaks via stimulated Raman scattering (SRS). Using peaks at 585, 600, and 616 nm as STED light we perform STED microscopy with resolution down to 20-30 nm. The nanosecond pulsed light source should prove valuable for all forms of microscopy requiring both brilliance and multiple wavelengths in the visible range.
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Affiliation(s)
- Brian R Rankin
- Department of NanoBiophotonics, Max-Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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234
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Abstract
We report sub-diffraction resolution in two-photon excitation (TPE) fluorescence microscopy achieved by merging this technique with stimulated-emission depletion (STED). We demonstrate an easy-to-implement and promising laser combination based on a short-pulse laser source for two-photon excitation and a continuous-wave (CW) laser source for resolution enhancement. Images of fluorescent nanoparticles and the immunostained transcription regulator NF kappaB in mammalian cell nuclei exhibit resolutions of <50 nm and approximately 70 nm in the focal plane, respectively, corresponding to a 4-5.4-fold improvement over the diffraction barrier.
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Affiliation(s)
- Gael Moneron
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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235
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Abstract
Achieving a spatial resolution that is not limited by the diffraction of light, recent developments of super-resolution fluorescence microscopy techniques allow the observation of many biological structures not resolvable in conventional fluorescence microscopy. New advances in these techniques now give them the ability to image three-dimensional (3D) structures, measure interactions by multicolor colocalization, and record dynamic processes in living cells at the nanometer scale. It is anticipated that super-resolution fluorescence microscopy will become a widely used tool for cell and tissue imaging to provide previously unobserved details of biological structures and processes.
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Affiliation(s)
- Bo Huang
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA.
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236
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Somekh MG, Hsu K, Pitter MC. Stochastic transfer function for structured illumination microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2009; 26:1630-7. [PMID: 19568299 DOI: 10.1364/josaa.26.001630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The stochastic transfer function extends the concept of the conventional transfer function by incorporating noise statistics, thus giving a measure of the signal-to-noise ratio at each spatial frequency. This provides a convenient and standardized metric to assess the trade-off in terms of spatial frequency bandwidth and signal-to-noise ratio for a diverse range of resolution enhancement techniques. We apply this concept to structured illumination microscopy and compare its noise performance as a function of frequency with the conventional wide-field fluorescent microscope. The result suggests how a hybrid algorithm further improves the photon efficiency of the structured illumination technique.
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Affiliation(s)
- Michael G Somekh
- Institute of Biophysics Imaging and Optical Science, The University of Nottingham, University Park, Nottingham, UK.
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237
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Odenheimer J, Heermann DW, Kreth G. Brownian dynamics simulations reveal regulatory properties of higher-order chromatin structures. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:749-56. [DOI: 10.1007/s00249-009-0486-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 05/06/2009] [Accepted: 05/13/2009] [Indexed: 01/04/2023]
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238
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Hirvonen LM, Wicker K, Mandula O, Heintzmann R. Structured illumination microscopy of a living cell. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:807-12. [DOI: 10.1007/s00249-009-0501-6] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 05/26/2009] [Accepted: 05/27/2009] [Indexed: 11/28/2022]
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239
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Blom H, Chmyrov A, Hassler K, Davis LM, Widengren J. Triplet-State Investigations of Fluorescent Dyes at Dielectric Interfaces Using Total Internal Reflection Fluorescence Correlation Spectroscopy. J Phys Chem A 2009; 113:5554-66. [DOI: 10.1021/jp8110088] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Hans Blom
- Department of Biomolecular Physics, Royal Institute of Technology, Stockholm, Sweden, and Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388
| | - Andriy Chmyrov
- Department of Biomolecular Physics, Royal Institute of Technology, Stockholm, Sweden, and Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388
| | - Kai Hassler
- Department of Biomolecular Physics, Royal Institute of Technology, Stockholm, Sweden, and Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388
| | - Lloyd M. Davis
- Department of Biomolecular Physics, Royal Institute of Technology, Stockholm, Sweden, and Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388
| | - Jerker Widengren
- Department of Biomolecular Physics, Royal Institute of Technology, Stockholm, Sweden, and Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388
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240
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Advances in the speed and resolution of light microscopy. Curr Opin Neurobiol 2009; 18:605-16. [PMID: 19375302 DOI: 10.1016/j.conb.2009.03.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 03/02/2009] [Accepted: 03/23/2009] [Indexed: 01/15/2023]
Abstract
Neurobiological processes occur on spatiotemporal scales spanning many orders of magnitude. Greater understanding of these processes therefore demands improvements in the tools used in their study. Here we review recent efforts to enhance the speed and resolution of one such tool, fluorescence microscopy, with an eye toward its application to neurobiological problems. On the speed front, improvements in beam scanning technology, signal generation rates, and photodamage mediation are bringing us closer to the goal of real-time functional imaging of extended neural networks. With regard to resolution, emerging methods of adaptive optics may lead to diffraction-limited imaging or much deeper imaging in optically inhomogeneous tissues, and super-resolution techniques may prove a powerful adjunct to electron microscopic methods for nanometric neural circuit reconstruction.
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241
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Scott TF, Kowalski BA, Sullivan AC, Bowman CN, McLeod RR. Two-color single-photon photoinitiation and photoinhibition for subdiffraction photolithography. Science 2009; 324:913-7. [PMID: 19359546 DOI: 10.1126/science.1167610] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Controlling and reducing the developed region initiated by photoexposure is one of the fundamental goals of optical lithography. Here, we demonstrate a two-color irradiation scheme whereby initiating species are generated by single-photon absorption at one wavelength while inhibiting species are generated by single-photon absorption at a second, independent wavelength. Co-irradiation at the second wavelength thus reduces the polymerization rate, delaying gelation of the material and facilitating enhanced spatial control over the polymerization. Appropriate overlapping of the two beams produces structures with both feature sizes and monomer conversions otherwise unobtainable with use of single- or two-photon absorption photopolymerization. Additionally, the generated inhibiting species rapidly recombine when irradiation with the second wavelength ceases, allowing for fast sequential exposures not limited by memory effects in the material and thus enabling fabrication of complex two- or three-dimensional structures.
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Affiliation(s)
- Timothy F Scott
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309-0424, USA
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242
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Huser T. Nano-biophotonics: new tools for chemical nano-analytics. Curr Opin Chem Biol 2009; 12:497-504. [PMID: 18786651 DOI: 10.1016/j.cbpa.2008.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
Abstract
The nondestructive chemical analysis of biological processes in the crowded intracellular environment, at cellular membranes, and between cells with a spatial resolution well beyond the diffraction limit is made possible through Nano-Biophotonics. A number of sophisticated schemes employing nanoparticles, nano-apertures, or shaping of the probe volume in the far field have significantly extended our knowledge about lipid rafts, macromolecular complexes, such as chromatin, vesicles, and cellular organelles, and their interactions and trafficking within the cell. Here, I review some of the most recent developments in Nano-Biophotonics that already are or soon will become relevant to the analysis of intracellular processes. The pros and cons of the various techniques will be discussed and an outlook of their prospects for the near future will be provided.
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Affiliation(s)
- Thomas Huser
- Department of Internal Medicine, and NSF Center for Biophotonics Science and Technology, University of California, Davis, 2700 Stockton Boulevard, Suite 1400, Sacramento, CA 95817, USA.
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243
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Hellriegel C, Gratton E. Real-time multi-parameter spectroscopy and localization in three-dimensional single-particle tracking. J R Soc Interface 2009; 6 Suppl 1:S3-14. [PMID: 18753123 PMCID: PMC2706464 DOI: 10.1098/rsif.2008.0313.focus] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 07/30/2008] [Indexed: 11/12/2022] Open
Abstract
Tracking of single particles in optical microscopy has been employed in studies ranging from material sciences to biophysics down to the level of single molecules. The technique intrinsically circumvents ensemble averaging and may therefore reveal directly mechanistic details of the involved dynamic processes. Such processes range from translational and rotational motion to spectral dynamics. We distinguish between conventional a posteriori tracking of objects (e.g. from the sequences of images) and the experimentally more refined 'on-the-fly' tracking technique. In this technique, the observation volume of the microscope is kept centred with respect to the moving object via a feedback algorithm. This approach brings a series of advantages in comparison with the tracking from images, ranging from a superior spatio-temporal resolution (2-50nm and 1-32ms) to the capability of inferring additional data (e.g. fluorescence lifetime, emission spectrum, polarization, intensity dynamics) from an object as it moves over several microns in three dimensions. In this contribution, we describe the principle of the tracking technique as implemented on a two-photon laser scanning microscope and illustrate its capabilities with experimental data, from particles labelled with different dyes moving in a liquid to the characterization of small fluorescently labelled protein assemblies in living cells.
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Affiliation(s)
- Christian Hellriegel
- />Laboratory for Fluorescence Dynamics and Department of Biomedical Engineering, University of California Irvine3120 Natural Sciences II, Irvine, CA 92697, USA
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244
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Burghardt TP, Li J, Ajtai K. Single myosin lever arm orientation in a muscle fiber detected with photoactivatable GFP. Biochemistry 2009; 48:754-65. [PMID: 19127992 PMCID: PMC2709297 DOI: 10.1021/bi8017703] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Myosin 2 is the molecular motor in muscle. It binds actin and executes a power stroke by rotating its lever arm through an angle of approximately 70 degrees to translate actin against resistive force. Myosin 2 has evolved to function optimally under crowded conditions where rates and equilibria of macromolecular reactions undergo major shifts relative to those measured in dilute solution. Hence, an important research objective is to detect in situ the lever arm orientation. Single-molecule measurements are preferred because they clarify ambiguities that are unavoidable with ensemble measurements; however, detecting single molecules in the condensed tissue medium where the myosin concentration exceeds 100 muM is challenging. A myosin light chain (MLC) tagged with photoactivatable green fluorescent protein (PAGFP) was constructed. The recombinant MLC physically and functionally replaced native MLC on the myosin lever arm in a permeabilized skeletal muscle fiber. Probe illumination volume was minimized using total internal reflection fluorescence microscopy, and PAGFP was sparsely photoactivated such that polarized fluorescence identified a single probe orientation. Several physiological states of the muscle fiber were characterized, revealing two distinct orientation populations in all states called straight and bent conformations. Conformation occupancy probability varies among fiber states with rigor and isometric contraction at extremes where straight and bent conformations predominate, respectively. Comparison to previous work on single rigor cross-bridges at the A-band periphery where the myosin concentration is low suggests molecular crowding in the A-band promotes occupancy of the straight myosin conformation [Burghardt, T. P., et al. (2007) Biophys. J. 93, 2226]. The latter may have a role in contraction because it provides additional free energy favoring completion of the cross-bridge power stroke.
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Affiliation(s)
- Thomas P Burghardt
- Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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245
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Deng S, Liu L, Cheng Y, Li R, Xu Z. Investigation of the influence of the aberration induced by a plane interface on STED microscopy. OPTICS EXPRESS 2009; 17:1714-25. [PMID: 19189001 DOI: 10.1364/oe.17.001714] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The structure of the inhibition patterns is important to the stimulated emission depletion (STED) microscopy. Usually, Laguerre- Gaussian (LG) beam and the central zero-intensity patterns created by inserting phase masks in Gaussian beams are used as the erase beam in STED microscopy. Aberration is generated when focusing beams through an interface between the media of the mismatched refractive indices. By use of the vectorial integral, the effects of such aberration on the shape of depletion patterns and the size of fluorescence emission spot in the STED microscopy are studied. Results are presented as a comparison between the aberration-free case and the aberrated cases.
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Affiliation(s)
- Suhui Deng
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
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246
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Sato S, Kozawa Y. Hollow vortex beams. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2009; 26:142-146. [PMID: 19109610 DOI: 10.1364/josaa.26.000142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hollow beam formation of radially and azimuthally polarized vortex beams, which has arbitrary topological charge, is analytically discussed under the strong focusing condition. The expressions for the electric fields of the focused vector-vortex beams are obtained based on a vector diffraction theory. The order of the Bessel function of the first kind appearing in the expressions indicates the ability to form hollow beams. Similar discussion is applied for different vortex beams, which are expressed by linear combination of radially and azimuthally polarized beams. Calculations of intensity profiles across the focus are also presented.
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Affiliation(s)
- Shunichi Sato
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan.
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247
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Donnert G, Eggeling C, Hell SW. Triplet-relaxation microscopy with bunched pulsed excitation. Photochem Photobiol Sci 2009; 8:481-5. [DOI: 10.1039/b903357m] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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248
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Visualizing cells at the nanoscale. Trends Biochem Sci 2008; 34:60-70. [PMID: 19101147 DOI: 10.1016/j.tibs.2008.10.011] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 10/29/2008] [Accepted: 10/29/2008] [Indexed: 11/22/2022]
Abstract
Cryogenic electron tomography (cryo- ET) enables the 3D visualization of biological material at a previously unseeable scale. Carefully controlled cryogenic specimen preparation avoids the artefacts that are notorious to conventional electron microscopy specimen preparation. To date, studies employing cryo- ET have mostly been restricted to isolated macromolecular assemblies, small prokaryotic cells or thin regions of eukaryotic cells owing to the limited penetration depth of electrons through ice-embedded preparations. Recent progress in cryosectioning makes it possible to acquire tomograms from many kinds of vitrified cells and tissues. The systematic and comprehensive interpretation of such tomograms will provide unprecedented insight into the molecular organization of cellular landscapes.
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249
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Abulrob A, Lu Z, Brunette E, Pulla D, Stanimirovic D, Johnston LJ. Near-field scanning optical microscopy detects nanoscale glycolipid domains in the plasma membrane. J Microsc 2008; 232:225-34. [PMID: 19017221 DOI: 10.1111/j.1365-2818.2008.02093.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The localization of asialo-GM1 in ordered membrane raft domains in HeLa cells has been examined using a combination of membrane fractionation and fluorescence imaging. The glycolipid is enriched in Triton X-100 insoluble membrane fractions that contain high concentrations of cholesterol and caveolin-1 but is also found in detergent soluble membrane fractions. Near-field fluorescence microscopy shows that a fraction of the asialo-GM1 is localized in small nanoscale clusters that have an upper limit for the average diameter of approximately 90 nm and are partially colocalized with caveolae membrane domains. In addition to clusters, a diffuse, non-clustered population of asialo-GM1 is observed and is hypothesized to correspond to glycolipid isolated in detergent soluble membrane fractions.
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Affiliation(s)
- A Abulrob
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, K1A 0R6, Canada
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Multilayer three-dimensional super resolution imaging of thick biological samples. Proc Natl Acad Sci U S A 2008; 105:20221-6. [PMID: 19088193 DOI: 10.1073/pnas.0810636105] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent advances in optical microscopy have enabled biological imaging beyond the diffraction limit at nanometer resolution. A general feature of most of the techniques based on photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM) has been the use of thin biological samples in combination with total internal reflection, thus limiting the imaging depth to a fraction of an optical wavelength. However, to study whole cells or organelles that are typically up to 15 microm deep into the cell, the extension of these methods to a three-dimensional (3D) super resolution technique is required. Here, we report an advance in optical microscopy that enables imaging of protein distributions in cells with a lateral localization precision better than 50 nm at multiple imaging planes deep in biological samples. The approach is based on combining the lateral super resolution provided by PALM with two-photon temporal focusing that provides optical sectioning. We have generated super-resolution images over an axial range of approximately 10 microm in both mitochondrially labeled fixed cells, and in the membranes of living S2 Drosophila cells.
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