1
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Jeong S, Kim J, Koh D, Lee JC. Simultaneously enhancing the resolution and signal-to-background ratio in STED optical nanoscopy via differential depletion. OPTICS EXPRESS 2023; 31:37549-37563. [PMID: 38017882 DOI: 10.1364/oe.505430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/08/2023] [Indexed: 11/30/2023]
Abstract
STED (stimulated emission depletion) far-field optical nanoscopy achieves resolution beyond the diffraction limit by depleting fluorescence at the periphery of excitation with a donut-shaped depletion laser. What is traded off with the superior resolution of STED nanoscopy is the unwanted elevation of structured background noise which hampers the quality of STED images. Here, we alleviate the background noise problem by adopting the differential stimulated emission depletion (diffSTED) approach. In diffSTED nanoscopy, signals obtained with different depletion strengths are compared and properly subtracted to remove two major background noise sources in STED nanoscopy. We show via simulations that by using diffSTED nanoscopy, background noise is significantly decreased, and the image contrast is improved. In addition, we show by simulation and analytical calculation that diffSTED improves resolution simultaneously. We assess the effect of different parameters, such as the STED beam intensity, depletion intensity ratio of two STED beams, and the subtraction factor, on the signal-to-background ratio (SBR) and the resolution of diffSTED nanoscopy. We introduce a logical algorithm to determine the optimal subtraction factor and the depletion intensity ratio. DiffSTED nanoscopy is a versatile technique that can be readily applied to any STED system without requiring any hardware modifications. We predict the wide applicability of diffSTED for its enhanced resolution, improved SBR, and easiness of implementation.
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2
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Chen YI, Chang YJ, Sun Y, Liao SC, Santacruz SR, Yeh HC. Spatial resolution enhancement in photon-starved STED imaging using deep learning-based fluorescence lifetime analysis. NANOSCALE 2023; 15:9449-9456. [PMID: 37159237 PMCID: PMC10460507 DOI: 10.1039/d3nr00305a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
As a super-resolution imaging method, stimulated emission depletion (STED) microscopy has unraveled fine intracellular structures and provided insights into nanoscale organizations in cells. Although image resolution can be further enhanced by continuously increasing the STED-beam power, the resulting photodamage and phototoxicity are major issues for real-world applications of STED microscopy. Here we demonstrate that, with 50% less STED-beam power, the STED image resolution can be improved up to 1.45-fold using the separation of photons by a lifetime tuning (SPLIT) scheme combined with a deep learning-based phasor analysis algorithm termed flimGANE (fluorescence lifetime imaging based on a generative adversarial network). This work offers a new approach for STED imaging in situations where only a limited photon budget is available.
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Affiliation(s)
- Yuan-I Chen
- Biomedical Engineering, University of Texas at Austin, Austin, TX, USA.
| | - Yin-Jui Chang
- Biomedical Engineering, University of Texas at Austin, Austin, TX, USA.
| | - Yuansheng Sun
- ISS, Inc., 1602 Newton Drive, Champaign, IL, 61822, USA
| | - Shih-Chu Liao
- ISS, Inc., 1602 Newton Drive, Champaign, IL, 61822, USA
| | - Samantha R Santacruz
- Biomedical Engineering, University of Texas at Austin, Austin, TX, USA.
- Electrical & Computer Engineering, University of Texas at Austin, Austin, TX, USA
- Institute for Neuroscience, University of Texas at Austin, Austin, TX, USA
| | - Hsin-Chih Yeh
- Biomedical Engineering, University of Texas at Austin, Austin, TX, USA.
- Texas Materials Institute, University of Texas at Austin, Austin, TX, USA
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3
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Han H, Wang L, Zhou H, Xing X, Guo Y, Zhu Y, Yan W, Qu J. Low-power compact continuous-wave stimulated emission depletion microscopy. JOURNAL OF BIOPHOTONICS 2023; 16:e202200233. [PMID: 36054472 DOI: 10.1002/jbio.202200233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Stimulated emission depletion (STED) microscopy can break the optical diffraction barrier and provide subdiffraction resolution. According to the STED superresolution imaging principle, the resolution of STED is positively related to the power of the depletion laser. However, high-laser power largely limits the study of living cells or living bodies. Moreover, the high complexity and high cost of conventional pulsed STED microscopy limit the application of this technique. Therefore, this paper describes a simple continuous-wave STED (CW-STED) system constructed on a 45 × 60 cm breadboard and combined with digitally enhanced (DE) technology; low-power superresolution imaging is realized, which has the advantages of reducing system complexity and cost. The low-system complexity, low cost, and low-power superresolution imaging features of CW-STED have great potential to advance the application of STED microscopy in biological research.
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Affiliation(s)
- HongYi Han
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Luwei Wang
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Hanqiu Zhou
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Xiuquan Xing
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Yong Guo
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Yinru Zhu
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Wei Yan
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Junle Qu
- Shenzhen Key Laboratory of Photonics and Biophotonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
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4
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Focus image scanning microscopy for sharp and gentle super-resolved microscopy. Nat Commun 2022; 13:7723. [PMID: 36513680 PMCID: PMC9747786 DOI: 10.1038/s41467-022-35333-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
To date, the feasibility of super-resolution microscopy for imaging live and thick samples is still limited. Stimulated emission depletion (STED) microscopy requires high-intensity illumination to achieve sub-diffraction resolution, potentially introducing photodamage to live specimens. Moreover, the out-of-focus background may degrade the signal stemming from the focal plane. Here, we propose a new method to mitigate these limitations without drawbacks. First, we enhance a STED microscope with a detector array, enabling image scanning microscopy (ISM). Therefore, we implement STED-ISM, a method that exploits the working principle of ISM to reduce the depletion intensity and achieve a target resolution. Later, we develop Focus-ISM, a strategy to improve the optical sectioning and remove the background of any ISM-based imaging technique, with or without a STED beam. The proposed approach requires minimal architectural changes to a conventional microscope but provides substantial advantages for live and thick sample imaging.
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5
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Ghithan JH, Noel JM, Roussel TJ, McCall MA, Alphenaar BW, Mendes SB. Photobleaching reduction in modulated super-resolution microscopy. Microscopy (Oxf) 2021; 70:278-288. [PMID: 33064828 DOI: 10.1093/jmicro/dfaa062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 11/13/2022] Open
Abstract
Important breakthroughs in far-field imaging techniques have been made since the first demonstrations of stimulated emission depletion (STED) microscopy. To date, the most straightforward and widespread deployment of STED microscopy has used continuous wave (CW) laser beams for both the excitation and depletion of fluorescence emission. A major drawback of the CW STED imaging technique has been photobleaching effects due to the high optical power needed in the depletion beam to reach sub-diffraction resolution. To overcome this hurdle, we have applied a synchronous detection approach based on modulating the excitation laser beam, while keeping the depletion beam at CW operation, and frequency filtering the collected signal with a lock-in amplifier to record solely the super-resolved fluorescence emission. We demonstrate here that such approach allows an important reduction in the optical power of both laser beams that leads to measurable decreases in photobleaching effects in STED microscopy. We report super-resolution images with relatively low powers for both the excitation and depletion beams. In addition, typical unwanted scattering effects and background signal generated from the depletion beam, which invariably arises from mismatches in refractive index in the material composing the sample, are largely reduced by using the modulated STED approach. The capability of acquiring super-resolution images with relatively low power is quite relevant for studying a variety of samples, but particularly important for biological species as exemplified in this work.
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Affiliation(s)
- Jafar H Ghithan
- University of Louisville, Department of Physics and Astronomy, 215 Eastern Pkwy, Louisville, Kentucky, United States, 40292
| | - Jennifer M Noel
- University of Louisville, Department of Anatomical Sciences and Neurobiology, 511 South Floyd, Louisville, Kentucky, United States, 40202
| | - Thomas J Roussel
- University of Louisville, Department of Bioengineering, J. B. Speed School of Engineering, Louisville, Kentucky, United States, 40292
| | - Maureen A McCall
- University of Louisville, Department of Ophthalmology and Visual Sciences, 301 E. Muhammad Ali Blvd., Louisville, Kentucky, United States, 40202
| | - Bruce W Alphenaar
- University of Louisville, Department of Electrical Engineering, J. B. Speed School of Engineering, Louisville, Kentucky, United States, 40292
| | - Sergio B Mendes
- University of Louisville, Department of Physics and Astronomy, 215 Eastern Pkwy, Louisville, Kentucky, United States, 40292
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6
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Gao Z, Wu P, Yin L, Kang B, Chen HY, Xu JJ. Super-resolution plasmonic imaging via scattering saturation STED. Chem Commun (Camb) 2021; 57:3492-3495. [PMID: 33690755 DOI: 10.1039/d0cc08375e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Based on the nonlinear plasmonic scattering response to the modulated excitation in time, we realized a single-wavelength super-resolution imaging method on a custom-built system which is named as a scattering saturation STED (ssSTED) microscope. A spatial resolution of λ/7 (65 nm) was obtained on 50 nm gold nanoparticles.
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Affiliation(s)
- Zhaoshuai Gao
- State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Centre of Chemistry for Life Sciences, Nanjing University, 163 Xianlin Road, Nanjing 210023, China.
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7
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Fernández A, Straw A, Distel M, Leitgeb R, Baltuska A, Verhoef AJ. Dynamic real-time subtraction of stray-light and background for multiphoton imaging. BIOMEDICAL OPTICS EXPRESS 2021; 12:288-302. [PMID: 33659077 PMCID: PMC7899518 DOI: 10.1364/boe.403255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/13/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
We introduce a new approach to reduce uncorrelated background signals from fluorescence imaging data, using real-time subtraction of background light. This approach takes advantage of the short fluorescence lifetime of most popular fluorescent activity reporters, and the low duty-cycle of ultrafast lasers. By synchronizing excitation and recording, laser-induced multiphoton fluorescence can be discriminated from background light levels with each laser pulse. We demonstrate the ability of our method to - in real-time - remove image artifacts that in a conventional imaging setup lead to clipping of the signal. In other words, our method enables imaging under conditions that in a conventional setup would yield corrupted data from which no accurate information can be extracted. This is advantageous in experimental setups requiring additional light sources for applications such as optogenetic stimulation.
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Affiliation(s)
- A Fernández
- IQSE and Department of Soil and Crop Sciences, Texas A&M University, 4242 TAMU, College Station, TX 77843, USA
- Photonics Institute, TU Wien, Gusshausstrasse 27-29/387, 1040 Vienna, Austria
- Centro Regional Universitario de Coclé, Universidad de Panamá, Penonomé, Coclé, Panama
| | - A Straw
- Institute of Biology I and Bernstein Center Freiburg, University of Freiburg, Hauptstrasse 1, 79104 Freiburg, Germany
| | - M Distel
- St. Anna Children's Cancer Research Institute, Zimmermannplatz 10, 1090 Vienna, Austria
| | - R Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20/4L, 1090 Vienna, Austria
| | - A Baltuska
- Photonics Institute, TU Wien, Gusshausstrasse 27-29/387, 1040 Vienna, Austria
| | - A J Verhoef
- IQSE and Department of Soil and Crop Sciences, Texas A&M University, 4242 TAMU, College Station, TX 77843, USA
- Photonics Institute, TU Wien, Gusshausstrasse 27-29/387, 1040 Vienna, Austria
- Centro Regional Universitario de Coclé, Universidad de Panamá, Penonomé, Coclé, Panama
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20/4L, 1090 Vienna, Austria
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8
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Li Y, Li C, Li Y, Hao X, Kuang C, Liu X. 3D resolution enhancement in saturated competition microscopy. APPLIED OPTICS 2020; 59:10661-10666. [PMID: 33361883 DOI: 10.1364/ao.404482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/25/2020] [Indexed: 06/12/2023]
Abstract
To overcome the diffraction barrier, super-resolution microscopy is contrived and has witnessed scientific developments in varying fields, especially in last few decades, such as stochastic optical reconstruction microscopy, stimulated emission depletion microscopy (STED), mirror-enhanced super-resolution microscopy (MEANS), and fluorescence emission difference microscopy (FED). Recently, saturated competition microscopy (SAC) was developed to realize high sub-diffraction resolution in either fluorescent or non-fluorescent imaging. Compared with STED, SAC features non-constraint in fluorescent dye selection. Nevertheless, the lateral resolution is limited in consideration of photobleaching side effects. Also, the axial resolution enhancement of SAC has not been demonstrated. In this study, a method, combining FED, MEANS, and SAC, is presented to improve the three-dimensional (3D) resolution. The numerical study reveals that the lateral resolution is close to 0.085λ and axial resolution can be enhanced to 0.184λ. In addition, the SNR is improved simultaneously. The availability to improve 3D resolution of SAC is believed to be significant for biological imaging in the future.
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9
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Coto Hernández I, Castello M, Tortarolo G, Jowett N, Diaspro A, Lanzanò L, Vicidomini G. Efficient two-photon excitation stimulated emission depletion nanoscope exploiting spatiotemporal information. NEUROPHOTONICS 2019; 6:045004. [PMID: 31720309 PMCID: PMC6830046 DOI: 10.1117/1.nph.6.4.045004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Stimulated emission depletion (STED) microscopy is a powerful bioimaging technique that theoretically provides molecular spatial resolution while preserving the most important assets of fluorescence microscopy. When combined with two-photon excitation (2PE) microscopy (2PE-STED), subdiffraction resolution may be achieved for thick biological samples. The most straightforward implementation of 2PE-STED microscopy entails introduction of an STED beam operating in continuous wave (CW) into a conventional Ti:sapphire-based 2PE microscope (2PE CW-STED). In this implementation, resolution enhancement is typically achieved using time-gated detection schemes, often resulting in drastic signal-to-noise/-background ratio (SNR/SBR) reductions. Herein, we employ a pixel-by-pixel phasor approach to discard fluorescence photons lacking super-resolution information to enhance image SNR/SBR in 2PE CW-STED microscopy. We compare this separation of photons by lifetime tuning approach against other postprocessing algorithms and combine it with image deconvolution to further optimize image quality.
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Affiliation(s)
- Iván Coto Hernández
- Massachusetts Eye and Ear and Harvard Medical School, Surgical Photonics and Engineering Laboratory, Boston, United States
| | - Marco Castello
- Istituto Italiano di Tecnologia, Molecular Microscopy and Spectroscopy, Genoa, Italy
| | - Giorgio Tortarolo
- Istituto Italiano di Tecnologia, Molecular Microscopy and Spectroscopy, Genoa, Italy
| | - Nate Jowett
- Massachusetts Eye and Ear and Harvard Medical School, Surgical Photonics and Engineering Laboratory, Boston, United States
| | - Alberto Diaspro
- Istituto Italiano di Tecnologia, Nanoscopy and NIC@IIT, Genoa, Italy
- University of Genoa, Department of Physics, Genoa, Italy
| | - Luca Lanzanò
- Istituto Italiano di Tecnologia, Nanoscopy and NIC@IIT, Genoa, Italy
| | - Giuseppe Vicidomini
- Istituto Italiano di Tecnologia, Molecular Microscopy and Spectroscopy, Genoa, Italy
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10
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Abstract
STimulated emission depletion (STED) nanoscopy has been proposed to extend greatly our capability of using light to study a variety of biological problems with nanometer-scale resolution. However, in practice the unwanted background noise degrades the STED image quality and precludes quantitative analysis. Here, we discuss the underlying sources of the background noise in STED images, and review current approaches to alleviate this problem, such as time-gating, anti-Stokes excitation removal, and off-focus incomplete depletion suppression. Progress in correcting uncorrelated background photons in fluorescence correlation spectroscopy combined with STED (STED-FCS) will also be discussed.
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Affiliation(s)
- Ye Ma
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America.,Departments of Biophysics and Biophysical Chemistry, Biophysics, Johns Hopkins University, Baltimore, MD, United States of America.,Howard Hughes Medical Institute, Baltimore, MD, United States of America.,Author to whom any correspondence should be addressed
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11
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Sarmento MJ, Oneto M, Pelicci S, Pesce L, Scipioni L, Faretta M, Furia L, Dellino GI, Pelicci PG, Bianchini P, Diaspro A, Lanzanò L. Exploiting the tunability of stimulated emission depletion microscopy for super-resolution imaging of nuclear structures. Nat Commun 2018; 9:3415. [PMID: 30143630 PMCID: PMC6109149 DOI: 10.1038/s41467-018-05963-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/27/2018] [Indexed: 11/23/2022] Open
Abstract
Imaging of nuclear structures within intact eukaryotic nuclei is imperative to understand the effect of chromatin folding on genome function. Recent developments of super-resolution fluorescence microscopy techniques combine high specificity, sensitivity, and less-invasive sample preparation procedures with the sub-diffraction spatial resolution required to image chromatin at the nanoscale. Here, we present a method to enhance the spatial resolution of a stimulated-emission depletion (STED) microscope based only on the modulation of the STED intensity during the acquisition of a STED image. This modulation induces spatially encoded variations of the fluorescence emission that can be visualized in the phasor plot and used to improve and quantify the effective spatial resolution of the STED image. We show that the method can be used to remove direct excitation by the STED beam and perform dual color imaging. We apply this method to the visualization of transcription and replication foci within intact nuclei of eukaryotic cells.
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Affiliation(s)
- Maria J Sarmento
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the A.S.C.R. v.v.i., Prague, Czech Republic
| | - Michele Oneto
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
| | - Simone Pelicci
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146, Genoa, Italy
| | - Luca Pesce
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146, Genoa, Italy
| | - Lorenzo Scipioni
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
| | - Mario Faretta
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Laura Furia
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Gaetano Ivan Dellino
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20142, Milan, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
- Department of Oncology and Hemato-Oncology, University of Milan, Via Santa Sofia 9, 20142, Milan, Italy
| | - Paolo Bianchini
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy
| | - Alberto Diaspro
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy.
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146, Genoa, Italy.
| | - Luca Lanzanò
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163, Genoa, Italy.
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12
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Li C, Liu S, Wang W, Liu W, Kuang C, Liu X. Recent research on stimulated emission depletion microscopy for reducing photobleaching. J Microsc 2018; 271:4-16. [PMID: 29600565 DOI: 10.1111/jmi.12698] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/23/2018] [Accepted: 02/28/2018] [Indexed: 12/11/2022]
Abstract
Stimulated emission depletion (STED) microscopy is a useful tool in investigation for super-resolution realm. By silencing the peripheral fluorophores of the excited spot, leaving only the very centre zone vigorous for fluorescence, the effective point spread function (PSF) could be immensely squeezed and subcellular structures, such as organelles, become discernable. Nevertheless, because of the low cross-section of stimulated emission and the short fluorescence lifetime, the depletion power density has to be extremely higher than the excitation power density and molecules are exposed in high risk of photobleaching. The existence of photobleaching greatly limits the research of STED in achieving higher resolution and more delicate imaging quality, as well as long-term and dynamic observation. Since the first experimental implementation of STED microscopy, researchers have lift out variety of methods and techniques to alleviate the problem. This paper would present some researches via conventional methods which have been explored and utilised relatively thoroughly, such as fast scanning, time-gating, two-photon excitation (TPE), triplet relaxation (T-Rex) and background suppression. Alternatively, several up-to-date techniques, especially adaptive illumination, would also be unveiled for discussion in this paper. The contrast and discussion of these modalities would play an important role in ameliorating the research of STED microscopy.
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Affiliation(s)
- C Li
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - S Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - W Wang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - W Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - C Kuang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China
| | - X Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China
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13
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DENG SUHUI, CHEN JIANFANG, GAO ZHAOSHUAI, FAN CHUNHAI, YAN QIURONG, WANG YUHAO. Effects of donor and acceptor's fluorescence lifetimes on the method of applying Förster resonance energy transfer in STED microscopy. J Microsc 2017; 269:59-65. [DOI: 10.1111/jmi.12608] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 06/22/2017] [Accepted: 07/10/2017] [Indexed: 11/30/2022]
Affiliation(s)
- SUHUI DENG
- School of Information Engineering; Nanchang University; Nanchang China
| | - JIANFANG CHEN
- Chinese Academy of Sciences; Shanghai Institute of Optics and Fine Mechanics; Shanghai China
| | - ZHAOSHUAI GAO
- Division of Physical Biology; and Bioimaging Center; Shanghai Synchrotron Radiation Facility, Chinese Academy of Sciences; Shanghai Institute of Applied Physics; Shanghai China
| | - CHUNHAI FAN
- Division of Physical Biology; and Bioimaging Center; Shanghai Synchrotron Radiation Facility, Chinese Academy of Sciences; Shanghai Institute of Applied Physics; Shanghai China
| | - QIURONG YAN
- School of Information Engineering; Nanchang University; Nanchang China
| | - YUHAO WANG
- School of Information Engineering; Nanchang University; Nanchang China
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14
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Castello M, Tortarolo G, Coto Hernández I, Deguchi T, Diaspro A, Vicidomini G. Removal of anti-Stokes emission background in STED microscopy by FPGA-based synchronous detection. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:053701. [PMID: 28571439 DOI: 10.1063/1.4983082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In stimulated emission depletion (STED) microscopy, the role of the STED beam is to de-excite, via stimulated emission, the fluorophores that have been previously excited by the excitation beam. This condition, together with specific beam intensity distributions, allows obtaining true sub-diffraction spatial resolution images. However, if the STED beam has a non-negligible probability to excite the fluorophores, a strong fluorescent background signal (anti-Stokes emission) reduces the effective resolution. For STED scanning microscopy, different synchronous detection methods have been proposed to remove this anti-Stokes emission background and recover the resolution. However, every method works only for a specific STED microscopy implementation. Here we present a user-friendly synchronous detection method compatible with any STED scanning microscope. It exploits a data acquisition (DAQ) card based on a field-programmable gate array (FPGA), which is progressively used in STED microscopy. In essence, the FPGA-based DAQ card synchronizes the fluorescent signal registration, the beam deflection, and the excitation beam interruption, providing a fully automatic pixel-by-pixel synchronous detection method. We validate the proposed method in both continuous wave and pulsed STED microscope systems.
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Affiliation(s)
- M Castello
- Molecular Microscopy and Spectroscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - G Tortarolo
- Molecular Microscopy and Spectroscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - I Coto Hernández
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - T Deguchi
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - A Diaspro
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - G Vicidomini
- Molecular Microscopy and Spectroscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
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15
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Gao P, Nienhaus GU. Precise background subtraction in stimulated emission double depletion nanoscopy. OPTICS LETTERS 2017; 42:831-834. [PMID: 28198876 DOI: 10.1364/ol.42.000831] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 01/26/2017] [Indexed: 06/06/2023]
Abstract
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. Here, we present a simple, yet powerful, method to determine the weight factor, which depends on the fluorescence decay, from a direct analysis of the acquired data. We vary the weight factor to identify its optimal value as the one for which the weight of high-frequency components in the spectrum of the acquired STEDD image is maximized. This strategy is also applicable to other differential approaches for background suppression in imaging.
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16
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Zeng Z, Xi P. Advances in three-dimensional super-resolution nanoscopy. Microsc Res Tech 2016; 79:893-898. [DOI: 10.1002/jemt.22719] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/18/2016] [Accepted: 06/23/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Zhiping Zeng
- Department of Biomedical Engineering; College of Engineering, Peking University; Beijing 100871 China
| | - Peng Xi
- Department of Biomedical Engineering; College of Engineering, Peking University; Beijing 100871 China
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17
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Castello M, Tortarolo G, Hernández IC, Bianchini P, Buttafava M, Boso G, Tosi A, Diaspro A, Vicidomini G. Gated-sted microscopy with subnanosecond pulsed fiber laser for reducing photobleaching. Microsc Res Tech 2016; 79:785-91. [DOI: 10.1002/jemt.22716] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/07/2016] [Accepted: 06/13/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Marco Castello
- Molecular Microscopy and Spectroscopy; Nanophysics, Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
- Department of Informatics Bioengineering Robotics and Systems Engineering; University of Genoa; Via Opera Pia 13 16145 Genoa Italy
| | - Giorgio Tortarolo
- Molecular Microscopy and Spectroscopy; Nanophysics, Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
- Department of Informatics Bioengineering Robotics and Systems Engineering; University of Genoa; Via Opera Pia 13 16145 Genoa Italy
| | | | - Paolo Bianchini
- Nanoscopy, Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Piazza Leonardo da Vinci, 32 Milan 20133 Italy
| | - Gianluca Boso
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Piazza Leonardo da Vinci, 32 Milan 20133 Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Piazza Leonardo da Vinci, 32 Milan 20133 Italy
| | - Alberto Diaspro
- Nanoscopy, Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
- Department of Physics; University of Genoa; Via Dodecaneso 33 Genoa 16146 Italy
- Nikon Imaging Center; Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy; Nanophysics, Istituto Italiano di Tecnologia; Via Morego 30 Genoa 16163 Italy
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18
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Coto Hernández I, Castello M, Lanzanò L, d'Amora M, Bianchini P, Diaspro A, Vicidomini G. Two-Photon Excitation STED Microscopy with Time-Gated Detection. Sci Rep 2016; 6:19419. [PMID: 26757892 PMCID: PMC4725939 DOI: 10.1038/srep19419] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/10/2015] [Indexed: 11/24/2022] Open
Abstract
We report on a novel two-photon excitation stimulated emission depletion (2PE-STED) microscope based on time-gated detection. The time-gated detection allows for the effective silencing of the fluorophores using moderate stimulated emission beam intensity. This opens the possibility of implementing an efficient 2PE-STED microscope with a stimulated emission beam running in a continuous-wave. The continuous-wave stimulated emission beam tempers the laser architecture's complexity and cost, but the time-gated detection degrades the signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) of the image. We recover the SNR and the SBR through a multi-image deconvolution algorithm. Indeed, the algorithm simultaneously reassigns early-photons (normally discarded by the time-gated detection) to their original positions and removes the background induced by the stimulated emission beam. We exemplify the benefits of this implementation by imaging sub-cellular structures. Finally, we discuss of the extension of this algorithm to future all-pulsed 2PE-STED implementationd based on time-gated detection and a nanosecond laser source.
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Affiliation(s)
- Iván Coto Hernández
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146, Genoa, Italy
| | - Marco Castello
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
- Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genoa, Via Opera Pia 13, 16145, Genoa, Italy
| | - Luca Lanzanò
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Marta d'Amora
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Paolo Bianchini
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Alberto Diaspro
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146, Genoa, Italy
- Nikon Imaging Center, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Giuseppe Vicidomini
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
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19
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Gautam V, Drury J, Choy JMC, Stricker C, Bachor HA, Daria VR. Improved two-photon imaging of living neurons in brain tissue through temporal gating. BIOMEDICAL OPTICS EXPRESS 2015; 6:4027-36. [PMID: 26504651 PMCID: PMC4605060 DOI: 10.1364/boe.6.004027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/11/2015] [Accepted: 09/11/2015] [Indexed: 05/05/2023]
Abstract
We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane's input resistance.
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Affiliation(s)
- Vini Gautam
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Jack Drury
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Julian M. C. Choy
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Christian Stricker
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
- Medical School, The Australian National University, Canberra, ACT 2601, Australia
| | - Hans-A. Bachor
- Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Vincent R. Daria
- John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
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20
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Wu Y, Wu X, Toro L, Stefani E. Resonant-scanning dual-color STED microscopy with ultrafast photon counting: A concise guide. Methods 2015; 88:48-56. [PMID: 26123183 DOI: 10.1016/j.ymeth.2015.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 11/29/2022] Open
Abstract
STED (stimulated emission depletion) is a popular super-resolution fluorescence microscopy technique. In this paper, we present a concise guide to building a resonant-scanning STED microscope with ultrafast photon-counting acquisition. The STED microscope has two channels, using a pulsed laser and a continuous-wave (CW) laser as the depletion laser source, respectively. The CW STED channel preforms time-gated detection to enhance optical resolution in this channel. We use a resonant mirror to attain high scanning speed and ultrafast photon counting acquisition to scan a large field of view, which help reduce photobleaching. We discuss some practical issues in building a STED microscope, including creating a hollow depletion beam profile, manipulating polarization, and monitoring optical aberration. We also demonstrate a STED image enhancement method using stationary wavelet expansion and image analysis methods to register objects and to quantify colocalization in STED microscopy.
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Affiliation(s)
- Yong Wu
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine, UCLA, United States; Cardiovascular Research Laboratory, David Geffen School of Medicine, UCLA, United States.
| | - Xundong Wu
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine, UCLA, United States
| | - Ligia Toro
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine, UCLA, United States; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, UCLA, United States; Cardiovascular Research Laboratory, David Geffen School of Medicine, UCLA, United States
| | - Enrico Stefani
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine, UCLA, United States; Department of Physiology, David Geffen School of Medicine, UCLA, United States; Cardiovascular Research Laboratory, David Geffen School of Medicine, UCLA, United States
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21
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Hernández IC, Buttafava M, Boso G, Diaspro A, Tosi A, Vicidomini G. Gated STED microscopy with time-gated single-photon avalanche diode. BIOMEDICAL OPTICS EXPRESS 2015; 6:2258-67. [PMID: 26114044 PMCID: PMC4473759 DOI: 10.1364/boe.6.002258] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/15/2015] [Accepted: 05/17/2015] [Indexed: 05/12/2023]
Abstract
Stimulated emission depletion (STED) microscopy provides fluorescence imaging with sub-diffraction resolution. Experimentally demonstrated at the end of the 90s, STED microscopy has gained substantial momentum and impact only in the last few years. Indeed, advances in many fields improved its compatibility with everyday biological research. Among them, a fundamental step was represented by the introduction in a STED architecture of the time-gated detection, which greatly reduced the complexity of the implementation and the illumination intensity needed. However, the benefits of the time-gated detection came along with a reduction of the fluorescence signal forming the STED microscopy images. The maximization of the useful (within the time gate) photon flux is then an important aspect to obtain super-resolved images. Here we show that by using a fast-gated single-photon avalanche diode (SPAD), i.e. a detector able to rapidly (hundreds picoseconds) switch-on and -off can improve significantly the signal-to-noise ratio (SNR) of the gated STED image. In addition to an enhancement of the image SNR, the use of the fast-gated SPAD reduces also the system complexity. We demonstrate these abilities both on calibration and biological sample. The experiments were carried on a gated STED microscope based on a STED beam operating in continuous-wave (CW), although the fast-gated SPAD is fully compatible with gated STED implementations based on pulsed STED beams.
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Affiliation(s)
- Iván Coto Hernández
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa,
Italy
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146, Genoa,
Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133, Milan,
Italy
| | - Gianluca Boso
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133, Milan,
Italy
- Group of Applied Physics, University of Geneva, Chemin de Pinchat 22, 1211, Geneva 4,
Switzerland
| | - Alberto Diaspro
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa,
Italy
- Department of Physics, University of Genoa, Via Dodecaneso 33, 16146, Genoa,
Italy
- Nikon Imaging Center, Via Morego 30, 16163, Genoa,
Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133, Milan,
Italy
| | - Giuseppe Vicidomini
- Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa,
Italy
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22
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Lanzanò L, Coto Hernández I, Castello M, Gratton E, Diaspro A, Vicidomini G. Encoding and decoding spatio-temporal information for super-resolution microscopy. Nat Commun 2015; 6:6701. [PMID: 25833391 PMCID: PMC4384168 DOI: 10.1038/ncomms7701] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 02/20/2015] [Indexed: 02/03/2023] Open
Abstract
The challenge of increasing the spatial resolution of an optical microscope beyond the diffraction limit can be reduced to a spectroscopy task by proper manipulation of the molecular states. The nanoscale spatial distribution of the molecules inside the detection volume of a scanning microscope can be encoded within the fluorescence dynamics and decoded by resolving the signal into its dynamics components. Here we present a robust and general method to decode this information using phasor analysis. As an example of the application of this method, we optically generate spatially controlled gradients in the fluorescence lifetime by stimulated emission. Spatial resolution can be increased indefinitely by increasing the number of resolved dynamics components up to a maximum determined by the amount of noise. We demonstrate that the proposed method provides nanoscale imaging of subcellular structures, opening new routes in super-resolution microscopy based on the encoding/decoding of spatial information through manipulation of molecular dynamics. Increasing the resolution of fluorescence microscopy is a fundamental need for modern cell biology. Lanzanò et al. demonstrate that arbitrary spatial resolution is, in principle, possible by encoding the fluorophore's spatial distribution information in the temporal dynamics of the fluorophore's transition.
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Affiliation(s)
- Luca Lanzanò
- Nanoscopy, Nanophysics Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
| | - Iván Coto Hernández
- 1] Nanoscopy, Nanophysics Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy [2] Department of Physics, University of Genoa, via Dodecaneso 33, Genoa 16146, Italy
| | - Marco Castello
- 1] Nanoscopy, Nanophysics Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy [2] Department of Computer Science, Bioengineering, Robotics and Systems Engineering, via Opera Pia 13, Genoa 16145, Italy
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California 92697, USA
| | - Alberto Diaspro
- 1] Nanoscopy, Nanophysics Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy [2] Department of Physics, University of Genoa, via Dodecaneso 33, Genoa 16146, Italy
| | - Giuseppe Vicidomini
- Nanoscopy, Nanophysics Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
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23
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Rosales T, Sackett DL, Xu J, Shi ZD, Xu B, Li H, Kaur G, Frohart E, Shenoy N, Cheal SM, Wu H, Dulcey AE, Hu Y, Li C, Lane K, Griffiths GL, Knutson JR. STAQ: A route toward low power, multicolor nanoscopy. Microsc Res Tech 2015; 78:343-55. [PMID: 25762506 DOI: 10.1002/jemt.22478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 02/01/2015] [Indexed: 11/11/2022]
Abstract
Nanoscopy has now become a real procedure in fluorescence microscopy of living cells. The STED/RESOLFT family of nanoscopy approaches has the best prospects for delivering high speed imaging, but the history of STED includes a continuing struggle to reduce the deactivation power applied, along with difficulties in achieving simultaneous multicolor images. In this manuscript, we present a concept for a similar real-time nanoscopy, using a new class of bipartite probes that separate the luminescent and quenching functions into two coupled molecules. In particular, the STAQ (Superresolution via Transiently Activated Quencher) example we show herein employs the excited state absorbance (not ground state) of the partner to accept energy from and quench the luminescent dye. The result is that much less deactivation power is needed for superresolved (∼50 nm) imaging. Moreover, the TAQ partner excited by the "donut" beam is shown to quench several different visible dyes via the same mechanism, opening the door to easier multicolor imaging. We demonstrate three dyes sharing the same deactivation and show examples of superresolved multicolor images. We suggest STAQ will facilitate the growth of real-time nanoscopy by reducing confounding photodamage within living cells while expanding the nanoscopist's palette.
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Affiliation(s)
- Tilman Rosales
- Optical Spectroscopy Section, Laboratory of Molecular Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Marylad, 20892-1412
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24
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Coto Hernàndez I, Peres C, Cella Zanacchi F, d'Amora M, Christodoulou S, Bianchini P, Diaspro A, Vicidomini G. A new filtering technique for removing anti-Stokes emission background in gated CW-STED microscopy. JOURNAL OF BIOPHOTONICS 2014; 7:376-80. [PMID: 24639427 DOI: 10.1002/jbio.201300208] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 02/24/2014] [Accepted: 02/24/2014] [Indexed: 05/26/2023]
Abstract
Stimulated emission depletion (STED) microscopy is a prominent approach of super-resolution optical microscopy, which allows cellular imaging with so far unprecedented unlimited spatial resolution. The introduction of time-gated detection in STED microscopy significantly reduces the (instantaneous) intensity required to obtain sub-diffraction spatial resolution. If the time-gating is combined with a STED beam operating in continuous wave (CW), a cheap and low labour demand implementation is obtained, the so called gated CW-STED microscope. However, time-gating also reduces the fluorescence signal which forms the image. Thereby, background sources such as fluorescence emission excited by the STED laser (anti-Stokes fluorescence) can reduce the effective resolution of the system. We propose a straightforward method for subtraction of anti-Stokes background. The method hinges on the uncorrelated nature of the anti-Stokes emission background with respect to the wanted fluorescence signal. The specific importance of the method towards the combination of two-photon-excitation with gated CW-STED microscopy is demonstrated.
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Affiliation(s)
- Ivàn Coto Hernàndez
- Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16136, Genoa, Italy; Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genoa, Italy
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25
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Vicidomini G, Coto Hernández I, d’Amora M, Cella Zanacchi F, Bianchini P, Diaspro A. Gated CW-STED microscopy: A versatile tool for biological nanometer scale investigation. Methods 2014; 66:124-30. [DOI: 10.1016/j.ymeth.2013.06.029] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 06/19/2013] [Accepted: 06/21/2013] [Indexed: 11/27/2022] Open
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26
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The Importance of Photon Arrival Times in STED Microscopy. SPRINGER SERIES ON FLUORESCENCE 2014. [DOI: 10.1007/4243_2014_73] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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27
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Chacko JV, Zanacchi FC, Diaspro A. Probing cytoskeletal structures by coupling optical superresolution and AFM techniques for a correlative approach. Cytoskeleton (Hoboken) 2013; 70:729-40. [PMID: 24027190 PMCID: PMC4265841 DOI: 10.1002/cm.21139] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 08/28/2013] [Accepted: 09/01/2013] [Indexed: 01/14/2023]
Abstract
In this article, we describe and show the application of some of the most advanced fluorescence superresolution techniques, STED AFM and STORM AFM microscopy towards imaging of cytoskeletal structures, such as microtubule filaments. Mechanical and structural properties can play a relevant role in the investigation of cytoskeletal structures of interest, such as microtubules, that provide support to the cell structure. In fact, the mechanical properties, such as the local stiffness and the elasticity, can be investigated by AFM force spectroscopy with tens of nanometers resolution. Force curves can be analyzed in order to obtain the local elasticity (and the Young's modulus calculation by fitting the force curves from every pixel of interest), and the combination with STED/STORM microscopy integrates the measurement with high specificity and yields superresolution structural information. This hybrid modality of superresolution-AFM working is a clear example of correlative multimodal microscopy.
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Affiliation(s)
- Jenu Varghese Chacko
- Nanophysics, Istituto Italiano di Tecnologia, Genova, Italy; Dipartimento di Fisica, Università degli Studi di Genova, Genova, Italy
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