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Luu P, Fraser SE, Schneider F. More than double the fun with two-photon excitation microscopy. Commun Biol 2024; 7:364. [PMID: 38531976 DOI: 10.1038/s42003-024-06057-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 03/15/2024] [Indexed: 03/28/2024] Open
Abstract
For generations researchers have been observing the dynamic processes of life through the lens of a microscope. This has offered tremendous insights into biological phenomena that span multiple orders of time- and length-scales ranging from the pure magic of molecular reorganization at the membrane of immune cells, to cell migration and differentiation during development or wound healing. Standard fluorescence microscopy techniques offer glimpses at such processes in vitro, however, when applied in intact systems, they are challenged by reduced signal strengths and signal-to-noise ratios that result from deeper imaging. As a remedy, two-photon excitation (TPE) microscopy takes a special place, because it allows us to investigate processes in vivo, in their natural environment, even in a living animal. Here, we review the fundamental principles underlying TPE aimed at basic and advanced microscopy users interested in adopting TPE for intravital imaging. We focus on applications in neurobiology, present current trends towards faster, wider and deeper imaging, discuss the combination with photon counting technologies for metabolic imaging and spectroscopy, as well as highlight outstanding issues and drawbacks in development and application of these methodologies.
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Affiliation(s)
- Peter Luu
- Translational Imaging Center, Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, 90089, USA
- Department of Biological Sciences, Division of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA
| | - Scott E Fraser
- Translational Imaging Center, Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, 90089, USA
- Department of Biological Sciences, Division of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, 90089, USA
- Alfred Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Falk Schneider
- Translational Imaging Center, Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, 90089, USA.
- Dana and David Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
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de Vito G, Turrini L, Müllenbroich C, Ricci P, Sancataldo G, Mazzamuto G, Tiso N, Sacconi L, Fanelli D, Silvestri L, Vanzi F, Pavone FS. Fast whole-brain imaging of seizures in zebrafish larvae by two-photon light-sheet microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:1516-1536. [PMID: 35414999 PMCID: PMC8973167 DOI: 10.1364/boe.434146] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 05/27/2023]
Abstract
Light-sheet fluorescence microscopy (LSFM) enables real-time whole-brain functional imaging in zebrafish larvae. Conventional one-photon LSFM can however induce undesirable visual stimulation due to the use of visible excitation light. The use of two-photon (2P) excitation, employing near-infrared invisible light, provides unbiased investigation of neuronal circuit dynamics. However, due to the low efficiency of the 2P absorption process, the imaging speed of this technique is typically limited by the signal-to-noise-ratio. Here, we describe a 2P LSFM setup designed for non-invasive imaging that enables quintuplicating state-of-the-art volumetric acquisition rate of the larval zebrafish brain (5 Hz) while keeping low the laser intensity on the specimen. We applied our system to the study of pharmacologically-induced acute seizures, characterizing the spatial-temporal dynamics of pathological activity and describing for the first time the appearance of caudo-rostral ictal waves (CRIWs).
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Affiliation(s)
- Giuseppe de Vito
- University of Florence, Department of Neuroscience, Psychology, Drug Research and Child Health, Viale Pieraccini 6, Florence, Italy, 50139, Italy
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- Co-first authors with equal contribution
| | - Lapo Turrini
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- University of Florence, Department of Physics and Astronomy, Via Sansone 1, Sesto Fiorentino 50019, Italy
- Co-first authors with equal contribution
| | - Caroline Müllenbroich
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- School of Physics and Astronomy, Kelvin Building, University of Glasgow, G12 8QQ, Glasgow, UK
- National Institute of Optics, National Research Council, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
| | - Pietro Ricci
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
| | - Giuseppe Sancataldo
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- University of Florence, Department of Physics and Astronomy, Via Sansone 1, Sesto Fiorentino 50019, Italy
| | - Giacomo Mazzamuto
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- National Institute of Optics, National Research Council, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
| | - Natascia Tiso
- University of Padova, Department of Biology, Via U. Bassi 58/B, Padova 35131, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- National Institute of Optics, National Research Council, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
| | - Duccio Fanelli
- University of Florence, Department of Physics and Astronomy, Via Sansone 1, Sesto Fiorentino 50019, Italy
| | - Ludovico Silvestri
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- University of Florence, Department of Physics and Astronomy, Via Sansone 1, Sesto Fiorentino 50019, Italy
- National Institute of Optics, National Research Council, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
| | - Francesco Vanzi
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- University of Florence, Department of Biology, Via Madonna del Piano 6, Sesto Fiorentino 50019, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
- University of Florence, Department of Physics and Astronomy, Via Sansone 1, Sesto Fiorentino 50019, Italy
- National Institute of Optics, National Research Council, Via Nello Carrara 1, Sesto Fiorentino 50019, Italy
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Takanezawa S, Saitou T, Imamura T. Wide field light-sheet microscopy with lens-axicon controlled two-photon Bessel beam illumination. Nat Commun 2021; 12:2979. [PMID: 34016994 PMCID: PMC8137944 DOI: 10.1038/s41467-021-23249-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/08/2021] [Indexed: 11/09/2022] Open
Abstract
Two-photon excitation can lower phototoxicity and improve penetration depth, but its narrow excitation range restricts its applications in light-sheet microscopy. Here, we propose simple illumination optics, a lens-axicon triplet composed of an axicon and two convex lenses, to generate longer extent Bessel beams. This unit can stretch the beam full width at half maximum of 600-1000 μm with less than a 4-μm waist when using a 10× illumination lens. A two-photon excitation digital scanned light-sheet microscope possessing this range of field of view and ~2-3-μm axial resolution is constructed and used to analyze the cellular dynamics over the whole body of medaka fish. We demonstrate long-term time-lapse observations over several days and high-speed recording with ~3 mm3 volume per 4 s of the embryos. Our system is minimal and suppresses laser power loss, which can broaden applications of two-photon excitation in light-sheet microscopy.
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Affiliation(s)
- Sota Takanezawa
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Matsuyama, Japan
| | - Takashi Saitou
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Matsuyama, Japan.
- Translational Research Center, Ehime University Hospital, Toon, Japan.
| | - Takeshi Imamura
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Matsuyama, Japan
- Translational Research Center, Ehime University Hospital, Toon, Japan
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4
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Deng S, Ding Z, Yuan D, Liu M, Zhou H. Investigation of the extended focusing capability of the spherical aberration to enlarge the field of view in light-sheet fluorescence microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2021; 38:19-24. [PMID: 33362148 DOI: 10.1364/josaa.410209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
In light-sheet fluorescence microscopy (LSFM), using Gaussian beams for light-sheet generation results in a trade-off between the thickness and the field of view (FOV). Here we present a theoretical analysis of using spherical aberration to enlarge the FOV while keeping the light-sheet thickness small. Such spherical aberration can arise when focusing beams through an interface between materials of mismatched refractive indices. The depth-of-focus extension of the Gaussian beam is achieved when using air objectives to focus light into the samples dipped in the immersion medium with a higher refractive index. By scanning this elongated beam, a thin light sheet with a wide FOV can be used for LSFM imaging. Meanwhile, the accompanied sidelobes with the spherical aberrated light sheet, which are mainly distributed in the rear part of the light sheet, are also discussed. Simulation results show that an extended FOV of 64.4µm is possible for an objective lens of NA=0.3, which is about 5 times that of the unaberrated case. For such an extended FOV, a comparatively thin thickness of 1.38µm as well as the first sidelobe about 11.1% of the peak intensity in the center are also demonstrated.
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Abstract
Embryonic development is highly complex and dynamic, requiring the coordination of numerous molecular and cellular events at precise times and places. Advances in imaging technology have made it possible to follow developmental processes at cellular, tissue, and organ levels over time as they take place in the intact embryo. Parallel innovations of in vivo probes permit imaging to report on molecular, physiological, and anatomical events of embryogenesis, but the resulting multidimensional data sets pose significant challenges for extracting knowledge. In this review, we discuss recent and emerging advances in imaging technologies, in vivo labeling, and data processing that offer the greatest potential for jointly deciphering the intricate cellular dynamics and the underlying molecular mechanisms. Our discussion of the emerging area of “image-omics” highlights both the challenges of data analysis and the promise of more fully embracing computation and data science for rapidly advancing our understanding of biology.
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Affiliation(s)
- Francesco Cutrale
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California 90089, USA
- Translational Imaging Center, University of Southern California, Los Angeles, California 90089, USA
| | - Scott E. Fraser
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California 90089, USA
- Translational Imaging Center, University of Southern California, Los Angeles, California 90089, USA
- Division of Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Le A. Trinh
- Translational Imaging Center, University of Southern California, Los Angeles, California 90089, USA
- Division of Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
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Funane T, Hou SS, Zoltowska KM, van Veluw SJ, Berezovska O, Kumar ATN, Bacskai BJ. Selective plane illumination microscopy (SPIM) with time-domain fluorescence lifetime imaging microscopy (FLIM) for volumetric measurement of cleared mouse brain samples. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:053705. [PMID: 29864842 PMCID: PMC6910582 DOI: 10.1063/1.5018846] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 04/24/2018] [Indexed: 05/02/2023]
Abstract
We have developed an imaging technique which combines selective plane illumination microscopy with time-domain fluorescence lifetime imaging microscopy (SPIM-FLIM) for three-dimensional volumetric imaging of cleared mouse brains with micro- to mesoscopic resolution. The main features of the microscope include a wavelength-adjustable pulsed laser source (Ti:sapphire) (near-infrared) laser, a BiBO frequency-doubling photonic crystal, a liquid chamber, an electrically focus-tunable lens, a cuvette based sample holder, and an air (dry) objective lens. The performance of the system was evaluated with a lifetime reference dye and micro-bead phantom measurements. Intensity and lifetime maps of three-dimensional human embryonic kidney (HEK) cell culture samples and cleared mouse brain samples expressing green fluorescent protein (GFP) (donor only) and green and red fluorescent protein [positive Förster (fluorescence) resonance energy transfer] were acquired. The results show that the SPIM-FLIM system can be used for sample sizes ranging from single cells to whole mouse organs and can serve as a powerful tool for medical and biological research.
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Affiliation(s)
- Tsukasa Funane
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Steven S Hou
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Katarzyna Marta Zoltowska
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Susanne J van Veluw
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Oksana Berezovska
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Anand T N Kumar
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA
| | - Brian J Bacskai
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, Massachusetts 02129, USA
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7
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Li R, Dong N, Ren F, Amekura H, Wang J, Chen F. Nonlinear Absorption Response Correlated to Embedded Ag Nanoparticles in BGO Single Crystal: From Two-Photon to Three-Photon Absorption. Sci Rep 2018; 8:1977. [PMID: 29386564 PMCID: PMC5792466 DOI: 10.1038/s41598-018-20446-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/15/2018] [Indexed: 11/23/2022] Open
Abstract
We report on the embedded silver (Ag) nanoparticles fabricated by Ag+ ion implantation into the Bi4Ge3O12 (BGO) crystal. Localized surface plasmon resonance (LSPR) phenomenon has been observed by linear optical absorption spectrum, which is accordance with the expectation based on Mie theory calculation. Further proofs are given by SRIM, TEM and SAED analysis, which explain the slight difference between experiment and calculation. Based on the z-scan system, it is found that the nonlinear optical response is converted from two-photon absorption to three-photon absorption under the 515 nm femtosecond pulse excitation within the LSPR band. The nonlinear absorption coefficient is measured to be ~3.1 × 10-9 cm/W (two-photon absorption coefficient) and ~8.9 × 10-14cm3/W2 (three-photon absorption coefficient) for pure BGO crystal and the sample embedded with Ag nanoparticles (Ag:BGO), respectively. Finally, we have proposed a model to explain the asymmetric nonlinear transmittance, which is in good agreement with the experimental results.
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Affiliation(s)
- Rang Li
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Ningning Dong
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai, 201800, China
| | - Feng Ren
- Department of Physics, Center for Ion beam Application and Center for Electron Microscopy, Wuhan University, Wuhan, 430072, China
| | - Hiro Amekura
- National Institute for Materials Science, 3-13 Sakura, Tsukuba, Ibaraki, 305-0003, Japan
| | - Jun Wang
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai, 201800, China
| | - Feng Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China.
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Männ L, Klingberg A, Gunzer M, Hasenberg M. Quantitative Visualization of Leukocyte Infiltrate in a Murine Model of Fulminant Myocarditis by Light Sheet Microscopy. J Vis Exp 2017. [PMID: 28605364 DOI: 10.3791/55450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently labelled structures in large biological specimens, and is down to cellular resolution. Meanwhile, the constant refinement of underlying protocols and the enhanced availability of specialized commercial systems enable us to investigate the microstructure of whole mouse organs and even allow for the characterization of cellular behavior in various live-cell imaging approaches. Here, we describe a protocol for the spatial whole-mount visualization and quantification of the CD45+ leukocyte population in inflamed mouse hearts. The method employs a transgenic mouse strain (CD11c.DTR)that has recently been shown to serve as a robust, inducible model for the study of the development of fulminant fatal myocarditis, characterized by lethal cardiac arrhythmias. This protocol includes myocarditis induction, intravital antibody-mediated cell staining, organ preparation, and LSFM with subsequent computer-assisted image post-processing. Although presented as a highly-adapted method for our particular scientific question, the protocol represents the blueprint of an easily adjustable system that can also target completely different fluorescent structures in other organs and even in other species.
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Affiliation(s)
- Linda Männ
- Department of Translational Skin Cancer Research, University of Duisburg/Essen
| | - Anika Klingberg
- Institute for Experimental Immunology and Imaging, University of Duisburg/Essen
| | - Matthias Gunzer
- Institute for Experimental Immunology and Imaging, University of Duisburg/Essen
| | - Mike Hasenberg
- Imaging Center Essen, Electron Microscopy Unit, University Hospital of Essen;
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9
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Integrated single- and two-photon light sheet microscopy using accelerating beams. Sci Rep 2017; 7:1435. [PMID: 28469191 PMCID: PMC5431168 DOI: 10.1038/s41598-017-01543-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/31/2017] [Indexed: 11/11/2022] Open
Abstract
We demonstrate the first light sheet microscope using propagation invariant, accelerating Airy beams that operates both in single- and two-photon modes. The use of the Airy beam permits us to develop an ultra compact, high resolution light sheet system without beam scanning. In two-photon mode, an increase in the field of view over the use of a standard Gaussian beam by a factor of six is demonstrated. This implementation for light sheet microscopy opens up new possibilities across a wide range of biomedical applications, especially for the study of neuronal processes.
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10
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Andilla J, Jorand R, Olarte OE, Dufour AC, Cazales M, Montagner YLE, Ceolato R, Riviere N, Olivo-Marin JC, Loza-Alvarez P, Lorenzo C. Imaging tissue-mimic with light sheet microscopy: A comparative guideline. Sci Rep 2017; 7:44939. [PMID: 28322312 PMCID: PMC5381005 DOI: 10.1038/srep44939] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/16/2017] [Indexed: 01/04/2023] Open
Abstract
Tissue mimics (TMs) on the scale of several hundred microns provide a beneficial cell culture configuration for in vitro engineered tissue and are currently under the spotlight in tissue engineering and regenerative medicine. Due to the cell density and size, TMs are fairly inaccessible to optical observation and imaging within these samples remains challenging. Light Sheet Fluorescence Microscopy (LSFM)- an emerging and attractive technique for 3D optical sectioning of large samples- appears to be a particularly well-suited approach to deal with them. In this work, we compared the effectiveness of different light sheet illumination modalities reported in the literature to improve resolution and/or light exposure for complex 3D samples. In order to provide an acute and fair comparative assessment, we also developed a systematic, computerized benchmarking method. The outcomes of our experiment provide meaningful information for valid comparisons and arises the main differences between the modalities when imaging different types of TMs.
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Affiliation(s)
- Jordi Andilla
- ICFO-Institut de Ciences Fotonique, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | | | - Omar E Olarte
- ICFO-Institut de Ciences Fotonique, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - Alexandre C Dufour
- Institut Pasteur BioImage Analysis Unit, F-75015, Paris, France.,CNRS, UMR-3691, F-75015 Paris, France
| | | | - Yoann L E Montagner
- Institut Pasteur BioImage Analysis Unit, F-75015, Paris, France.,CNRS, UMR-3691, F-75015 Paris, France
| | - Romain Ceolato
- Onera, The French Aerospace Lab, F-31100 Toulouse, France
| | | | | | - Pablo Loza-Alvarez
- ICFO-Institut de Ciences Fotonique, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
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Stoltzfus CR, Rebane A. Optimizing ultrafast illumination for multiphoton-excited fluorescence imaging. BIOMEDICAL OPTICS EXPRESS 2016; 7:1768-82. [PMID: 27231620 PMCID: PMC4871080 DOI: 10.1364/boe.7.001768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/24/2016] [Accepted: 04/05/2016] [Indexed: 05/14/2023]
Abstract
We study the optimal conditions for high throughput two-photon excited fluorescence (2PEF) and three-photon excited fluorescence (3PEF) imaging using femtosecond lasers. We derive relations that allow maximization of the rate of imaging depending on the average power, pulse repetition rate, and noise characteristics of the laser, as well as on the size and structure of the sample. We perform our analysis using ~100 MHz, ~1 MHz and 1 kHz pulse rates and using both a tightly-focused illumination beam with diffraction-limited image resolution, as well loosely focused illumination with a relatively low image resolution, where the latter utilizes separate illumination and fluorescence detection beam paths. Our theoretical estimates agree with the experiments, which makes our approach especially useful for optimizing high throughput imaging of large samples with a field-of-view up to 10x10 cm(2).
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Affiliation(s)
| | - Aleksander Rebane
- Physics Department, Montana State University, Bozeman MT 59717, USA
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
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