1
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Ward EN, McClelland RM, Lamb JR, Rubio-Sánchez R, Christensen CN, Mazumder B, Kapsiani S, Mascheroni L, Di Michele L, Kaminski Schierle GS, Kaminski CF. Fast, multicolour optical sectioning over extended fields of view with patterned illumination and machine learning. BIOMEDICAL OPTICS EXPRESS 2024; 15:1074-1088. [PMID: 38404329 PMCID: PMC10890859 DOI: 10.1364/boe.510912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/22/2023] [Accepted: 01/09/2024] [Indexed: 02/27/2024]
Abstract
Structured illumination can reject out-of-focus signal from a sample, enabling high-speed and high-contrast imaging over large areas with widefield detection optics. However, this optical sectioning technique is currently limited by image reconstruction artefacts and poor performance at low signal-to-noise ratios. We combine multicolour interferometric pattern generation with machine learning to achieve high-contrast, real-time reconstruction of image data that is robust to background noise and sample motion. We validate the method in silico and demonstrate imaging of diverse specimens, from fixed and live biological samples to synthetic biosystems, reconstructing data live at 11 Hz across a 44 × 44μm2 field of view, and demonstrate image acquisition speeds exceeding 154 Hz.
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Affiliation(s)
- Edward N. Ward
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Rebecca M. McClelland
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Jacob R. Lamb
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Roger Rubio-Sánchez
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
- fabriCELL, Molecular Sciences Research Hub,
Imperial College London, London, W12 0BZ,
UK
| | - Charles N. Christensen
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Bismoy Mazumder
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Sofia Kapsiani
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Luca Mascheroni
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Lorenzo Di Michele
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
- fabriCELL, Molecular Sciences Research Hub,
Imperial College London, London, W12 0BZ,
UK
| | | | - Clemens F. Kaminski
- Department of Chemical Engineering and
Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
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2
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Matsuda Y, Katayama S, Ikami T, Egami Y, Nagai H. Structured light illumination for pressure-sensitive paint measurement under ambient light. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:055101. [PMID: 35649770 DOI: 10.1063/5.0089000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023]
Abstract
We propose a pressure-sensitive paint (PSP) method under ambient light based on structured light illumination. In the PSP method, pressure is obtained by measuring the variation of the emission light intensity from a PSP coating when it is illuminated by a light source. Since the extraction of the emission light from ambient light is difficult in the conventional PSP method, the existence of ambient light induces a noticeable measurement error. While spatially uniform light is used as illumination light in the conventional PSP method, structured light, the spatial intensity of which is actively controlled, is used in the proposed method. By measuring the PSP emission by varying the spatial pattern of the structured light illumination, one can eliminate ambient light, which is not synchronized with the structured light and can measure pressure without the effect of ambient light. In this study, we demonstrate the pressure measurement under ambient light using structured light with a sinusoidal wave generated by a digital mirror device. The measured pressure agrees well with the pressure measured by a pressure transducer connected to a pressure tap. The proposed method is promising under ambient light conditions.
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Affiliation(s)
- Yu Matsuda
- Department of Modern Mechanical Engineering, Waseda University, 3-4-1 Ookubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Satoshi Katayama
- Department of Modern Mechanical Engineering, Waseda University, 3-4-1 Ookubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Tsubasa Ikami
- Department of Aerospace Engineering, Tohoku University, 6-6-01 Aoba, Arakaki, Aoba-ku, Sendai, Miyagi-Prefecture 980-8579, Japan
| | - Yasuhiro Egami
- Department of Mechanical Engineering, Aichi Institute of Technology, 1247 Yachigusa, Yakusa-Cho, Toyota, Aichi-Prefecture 470-0392, Japan
| | - Hiroki Nagai
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi-Prefecture 980-8577, Japan
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3
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Schneckenburger H. Lasers in Live Cell Microscopy. Int J Mol Sci 2022; 23:ijms23095015. [PMID: 35563406 PMCID: PMC9102032 DOI: 10.3390/ijms23095015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022] Open
Abstract
Due to their unique properties—coherent radiation, diffraction limited focusing, low spectral bandwidth and in many cases short light pulses—lasers play an increasing role in live cell microscopy. Lasers are indispensable tools in 3D microscopy, e.g., confocal, light sheet or total internal reflection microscopy, as well as in super-resolution microscopy using wide-field or confocal methods. Further techniques, e.g., spectral imaging or fluorescence lifetime imaging (FLIM) often depend on the well-defined spectral or temporal properties of lasers. Furthermore, laser microbeams are used increasingly for optical tweezers or micromanipulation of cells. Three exemplary laser applications in live cell biology are outlined. They include fluorescence diagnosis, in particular in combination with Förster Resonance Energy Transfer (FRET), photodynamic therapy as well as laser-assisted optoporation, and demonstrate the potential of lasers in cell biology and—more generally—in biomedicine.
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4
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High-speed compressed-sensing fluorescence lifetime imaging microscopy of live cells. Proc Natl Acad Sci U S A 2021; 118:2004176118. [PMID: 33431663 DOI: 10.1073/pnas.2004176118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We present high-resolution, high-speed fluorescence lifetime imaging microscopy (FLIM) of live cells based on a compressed sensing scheme. By leveraging the compressibility of biological scenes in a specific domain, we simultaneously record the time-lapse fluorescence decay upon pulsed laser excitation within a large field of view. The resultant system, referred to as compressed FLIM, can acquire a widefield fluorescence lifetime image within a single camera exposure, eliminating the motion artifact and minimizing the photobleaching and phototoxicity. The imaging speed, limited only by the readout speed of the camera, is up to 100 Hz. We demonstrated the utility of compressed FLIM in imaging various transient dynamics at the microscopic scale.
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5
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Hinsdale TA, Malik BH, Cheng S, Benavides OR, Giger ML, Wright JM, Patel PB, Jo JA, Maitland KC. Enhanced detection of oral dysplasia by structured illumination fluorescence lifetime imaging microscopy. Sci Rep 2021; 11:4984. [PMID: 33654229 PMCID: PMC7925521 DOI: 10.1038/s41598-021-84552-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/17/2021] [Indexed: 12/15/2022] Open
Abstract
We demonstrate that structured illumination microscopy has the potential to enhance fluorescence lifetime imaging microscopy (FLIM) as an early detection method for oral squamous cell carcinoma. FLIM can be used to monitor or detect changes in the fluorescence lifetime of metabolic cofactors (e.g. NADH and FAD) associated with the onset of carcinogenesis. However, out of focus fluorescence often interferes with this lifetime measurement. Structured illumination fluorescence lifetime imaging (SI-FLIM) addresses this by providing depth-resolved lifetime measurements, and applied to oral mucosa, can localize the collected signal to the epithelium. In this study, the hamster model of oral carcinogenesis was used to evaluate SI-FLIM in premalignant and malignant oral mucosa. Cheek pouches were imaged in vivo and correlated to histopathological diagnoses. The potential of NADH fluorescence signal and lifetime, as measured by widefield FLIM and SI-FLIM, to differentiate dysplasia (pre-malignancy) from normal tissue was evaluated. ROC analysis was carried out with the task of discriminating between normal tissue and mild dysplasia, when changes in fluorescence characteristics are localized to the epithelium only. The results demonstrate that SI-FLIM (AUC = 0.83) is a significantly better (p-value = 0.031) marker for mild dysplasia when compared to widefield FLIM (AUC = 0.63).
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Affiliation(s)
- Taylor A Hinsdale
- Department of Biomedical Engineering, Texas A&M University, College Station, USA
- Delft University of Technology, Delft, The Netherlands
| | - Bilal H Malik
- Department of Biomedical Engineering, Texas A&M University, College Station, USA
- QT Imaging, Inc, 3 Hamilton Landing, Suite 160, Novato, CA, 94949, USA
| | - Shuna Cheng
- Department of Biomedical Engineering, Texas A&M University, College Station, USA
| | - Oscar R Benavides
- Department of Biomedical Engineering, Texas A&M University, College Station, USA
| | | | - John M Wright
- Department of Diagnostic Science, Texas A&M College of Dentistry, Dallas, USA
| | - Paras B Patel
- Department of Diagnostic Science, Texas A&M College of Dentistry, Dallas, USA
| | - Javier A Jo
- Department of Biomedical Engineering, Texas A&M University, College Station, USA
- Department of Electrical and Computer Engineering, University of Oklahoma, Norman, USA
| | - Kristen C Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, USA.
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6
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Li Z, Zhang Q, Chou SW, Newman Z, Turcotte R, Natan R, Dai Q, Isacoff EY, Ji N. Fast widefield imaging of neuronal structure and function with optical sectioning in vivo. SCIENCE ADVANCES 2020; 6:eaaz3870. [PMID: 32494711 PMCID: PMC7209992 DOI: 10.1126/sciadv.aaz3870] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 02/18/2020] [Indexed: 05/19/2023]
Abstract
Optical microscopy, owing to its noninvasiveness and subcellular resolution, enables in vivo visualization of neuronal structure and function in the physiological context. Optical-sectioning structured illumination microscopy (OS-SIM) is a widefield fluorescence imaging technique that uses structured illumination patterns to encode in-focus structures and optically sections 3D samples. However, its application to in vivo imaging has been limited. In this study, we optimized OS-SIM for in vivo neural imaging. We modified OS-SIM reconstruction algorithms to improve signal-to-noise ratio and correct motion-induced artifacts in live samples. Incorporating an adaptive optics (AO) module to OS-SIM, we found that correcting sample-induced optical aberrations was essential for achieving accurate structural and functional characterizations in vivo. With AO OS-SIM, we demonstrated fast, high-resolution in vivo imaging with optical sectioning for structural imaging of mouse cortical neurons and zebrafish larval motor neurons, and functional imaging of quantal synaptic transmission at Drosophila larval neuromuscular junctions.
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Affiliation(s)
- Ziwei Li
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Qinrong Zhang
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shih-Wei Chou
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Zachary Newman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Raphaël Turcotte
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ryan Natan
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Qionghai Dai
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Ehud Y. Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
- Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, Berkeley, CA 94720, USA
| | - Na Ji
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Corresponding author.
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7
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Datta R, Heaster TM, Sharick JT, Gillette AA, Skala MC. Fluorescence lifetime imaging microscopy: fundamentals and advances in instrumentation, analysis, and applications. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-43. [PMID: 32406215 PMCID: PMC7219965 DOI: 10.1117/1.jbo.25.7.071203] [Citation(s) in RCA: 312] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/24/2020] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to distinguish the unique molecular environment of fluorophores. FLIM measures the time a fluorophore remains in an excited state before emitting a photon, and detects molecular variations of fluorophores that are not apparent with spectral techniques alone. FLIM is sensitive to multiple biomedical processes including disease progression and drug efficacy. AIM We provide an overview of FLIM principles, instrumentation, and analysis while highlighting the latest developments and biological applications. APPROACH This review covers FLIM principles and theory, including advantages over intensity-based fluorescence measurements. Fundamentals of FLIM instrumentation in time- and frequency-domains are summarized, along with recent developments. Image segmentation and analysis strategies that quantify spatial and molecular features of cellular heterogeneity are reviewed. Finally, representative applications are provided including high-resolution FLIM of cell- and organelle-level molecular changes, use of exogenous and endogenous fluorophores, and imaging protein-protein interactions with Förster resonance energy transfer (FRET). Advantages and limitations of FLIM are also discussed. CONCLUSIONS FLIM is advantageous for probing molecular environments of fluorophores to inform on fluorophore behavior that cannot be elucidated with intensity measurements alone. Development of FLIM technologies, analysis, and applications will further advance biological research and clinical assessments.
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Affiliation(s)
- Rupsa Datta
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Tiffany M. Heaster
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Joe T. Sharick
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Amani A. Gillette
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin, Department of Biomedical Engineering, Madison, Wisconsin, United States
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8
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Wai RB, Ramesh N, Aiello CD, Raybin JG, Zeltmann SE, Bischak CG, Barnard E, Aloni S, Ogletree DF, Minor AM, Ginsberg NS. Resolving Enhanced Mn 2+ Luminescence near the Surface of CsPbCl 3 with Time-Resolved Cathodoluminescence Imaging. J Phys Chem Lett 2020; 11:2624-2629. [PMID: 32191469 DOI: 10.1021/acs.jpclett.0c00574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mn2+ doping of lead halide perovskites has garnered recent interest because it produces stable orange luminescence in tandem with perovskite emission. Here, we observe enhanced Mn2+ luminescence at the edges of Mn2+-doped CsPbCl3 perovskite microplates and suggest an explanation for its origin using the high spatiotemporal resolution of time-resolved cathodoluminescence (TRCL) imaging. We reveal two luminescent decay components that we attribute to two different Mn2+ populations. While each component appears to be present both near the surface and in the bulk, the origin of the intensity variation stems from a higher proportion of the longer lifetime component near the perovskite surface. We suggest that this higher emission is caused by an increased probability of electron-hole recombination on Mn2+ near the perovskite surface due to an increased trap concentration there. This observation suggests that such surface features have yet untapped potential to enhance emissive properties via control of surface-to-volume ratio.
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Affiliation(s)
- Rebecca B Wai
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
| | - Namrata Ramesh
- Department of Physics, University of California, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
| | - Clarice D Aiello
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Jonathan G Raybin
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
| | - Steven E Zeltmann
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
| | - Connor G Bischak
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Edward Barnard
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Shaul Aloni
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - D Frank Ogletree
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew M Minor
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
| | - Naomi S Ginsberg
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Department of Physics, University of California, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
- STROBE, NSF Science & Technology Center, Berkeley, California 94720, United States
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9
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Tu S, Liu Q, Liu X, Liu W, Zhang Z, Luo T, Kuang C, Liu X, Hao X. Fast reconstruction algorithm for structured illumination microscopy. OPTICS LETTERS 2020; 45:1567-1570. [PMID: 32164018 DOI: 10.1364/ol.387888] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Structured illumination microscopy (SIM) is a powerful technique for providing super-resolution imaging, but its reconstruction algorithm, i.e., linear reconstruction structured illumination microscopy (LRSIM) algorithm in the Fourier domain, limits the imaging speed due to its computational effort. Here, we present a novel reconstruction algorithm that can directly process SIM data in the spatial domain. Compared to LRSIM, this approach uses the same number of frames to achieve a comparable resolution but with a much faster processing speed. Our algorithm was verified on both simulated and experimental data using sinusoidal pattern illumination. Moreover, this algorithm is also applicable for speckle pattern illumination.
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10
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Vinegoni C, Feruglio PF, Gryczynski I, Mazitschek R, Weissleder R. Fluorescence anisotropy imaging in drug discovery. Adv Drug Deliv Rev 2019; 151-152:262-288. [PMID: 29410158 PMCID: PMC6072632 DOI: 10.1016/j.addr.2018.01.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 12/15/2022]
Abstract
Non-invasive measurement of drug-target engagement can provide critical insights in the molecular pharmacology of small molecule drugs. Fluorescence polarization/fluorescence anisotropy measurements are commonly employed in protein/cell screening assays. However, the expansion of such measurements to the in vivo setting has proven difficult until recently. With the advent of high-resolution fluorescence anisotropy microscopy it is now possible to perform kinetic measurements of intracellular drug distribution and target engagement in commonly used mouse models. In this review we discuss the background, current advances and future perspectives in intravital fluorescence anisotropy measurements to derive pharmacokinetic and pharmacodynamic measurements in single cells and whole organs.
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Affiliation(s)
- Claudio Vinegoni
- Center for System Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Paolo Fumene Feruglio
- Center for System Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Department of Neurological, Biomedical and Movement Sciences, University of Verona, Verona, Italy
| | - Ignacy Gryczynski
- University of North Texas Health Science Center, Institute for Molecular Medicine, Fort Worth, TX, United States
| | - Ralph Mazitschek
- Center for System Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Ralph Weissleder
- Center for System Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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11
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McCarthy ME, Birtwistle MR. Highly Multiplexed, Quantitative Tissue Imaging at Cellular Resolution. CURRENT PATHOBIOLOGY REPORTS 2019. [DOI: 10.1007/s40139-019-00203-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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12
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Dobek K, Baranowski M. Multi-planar imaging using the thermal lensing effect. APPLIED OPTICS 2019; 58:5883-5891. [PMID: 31503895 DOI: 10.1364/ao.58.005883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/07/2019] [Indexed: 06/10/2023]
Abstract
The application of a thermal lens, formed by a laser beam, in the imaging of objects lying in three different planes is reported for the first time, to the best of our knowledge. The objects' planes are separated by a distance surpassing the depth-of-field of the imaging setup. It is the local formation of two thermal lenses near the intermediate image plane in a thermo-optical material that allows for the observation of two additional objects.
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13
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Zhang Y, Lang S, Wang H, Liao J, Gong Y. Super-resolution algorithm based on Richardson-Lucy deconvolution for three-dimensional structured illumination microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:173-178. [PMID: 30874094 DOI: 10.1364/josaa.36.000173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/11/2018] [Indexed: 05/21/2023]
Abstract
Three-dimensional structured illumination microscopy (3D-SIM) is a wide-field super-resolution technique in fluorescent imaging that can double the resolution beyond its classical limit. We introduce, to the best of our knowledge, a new 3D reconstruction algorithm based on the Richardson-Lucy deconvolution. The 3D-SIM imaging principle and the reconstruction steps are demonstrated in detail. Microspheres and biological specimen are used to present the performance of this method. The background of the out-of-focus portion is effectively suppressed, and true optical sectioning and super-resolution can be achieved simultaneously. For the custom-built 3D-SIM and this reconstruction algorithm, the measured resolution was 99.5±5 nm laterally and 294±9 nm axially.
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14
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Kristensson E, Berrocal E. Crossed patterned structured illumination for the analysis and velocimetry of transient turbid media. Sci Rep 2018; 8:11751. [PMID: 30082685 PMCID: PMC6079086 DOI: 10.1038/s41598-018-30233-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/18/2018] [Indexed: 12/04/2022] Open
Abstract
Imaging through turbid environments is experimentally challenging due to multiple light scattering. Structured laser illumination has proven to be effective to minimize errors arising from this phenomenon, allowing the interior of optically dense media to be observed. However, in order to preserve the image spatial resolution while suppressing the intensity contribution from multiple light scattering, the method relies on multiple acquisitions and thus sequential illumination. These requirements significantly limit the usefulness of structured illumination when imaging highly transient events. Here we present a method for achieving snapshot visualizations using structured illumination, where the spatial frequency domain is increased by a factor of two compared to past structured illumination snapshots. Our approach uses two crossed intensity-modulated patterns, allowing us to expand the spatial frequency response of the extracted data. The snapshot capability of this imaging approach allows tracking single particles and opens up for the extraction of velocity vectors by combining it with standard particle tracking/image velocimetry (PTV or PIV) equipment. In this paper we demonstrate the capabilities of this new method and, for the first time, use structured illumination to extract velocity vectors in 2D in a transient turbid medium, in this case an optically dense atomizing spray.
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Affiliation(s)
- Elias Kristensson
- Department of Physics, Division of Combustion Physics, Lund University, Lund, Sweden.
| | - Edouard Berrocal
- Department of Physics, Division of Combustion Physics, Lund University, Lund, Sweden.
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), Universität Erlangen-Nürnberg, Erlangen, Germany.
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15
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Le Marois A, Suhling K. Quantitative Live Cell FLIM Imaging in Three Dimensions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1035:31-48. [PMID: 29080129 DOI: 10.1007/978-3-319-67358-5_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In this chapter, the concept of fluorescence lifetime and its utility in quantitative live cell imaging will be introduced, along with methods to record and analyze FLIM data. Relevant applications in 3D tissue and live cell imaging, including multiplexed FLIM detection, will also be detailed.
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Affiliation(s)
- Alix Le Marois
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK.
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16
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Silva SF, Domingues JP, Morgado AM. Accurate Rapid Lifetime Determination on Time-Gated FLIM Microscopy with Optical Sectioning. JOURNAL OF HEALTHCARE ENGINEERING 2018; 2018:1371386. [PMID: 29599938 PMCID: PMC5823430 DOI: 10.1155/2018/1371386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 11/21/2017] [Accepted: 12/03/2017] [Indexed: 11/18/2022]
Abstract
Time-gated fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to assess the biochemistry of cells and tissues. When applied to living thick samples, it is hampered by the lack of optical sectioning and the need of acquiring many images for an accurate measurement of fluorescence lifetimes. Here, we report on the use of processing techniques to overcome these limitations, minimizing the acquisition time, while providing optical sectioning. We evaluated the application of the HiLo and the rapid lifetime determination (RLD) techniques for accurate measurement of fluorescence lifetimes with optical sectioning. HiLo provides optical sectioning by combining the high-frequency content from a standard image, obtained with uniform illumination, with the low-frequency content of a second image, acquired using structured illumination. Our results show that HiLo produces optical sectioning on thick samples without degrading the accuracy of the measured lifetimes. We also show that instrument response function (IRF) deconvolution can be applied with the RLD technique on HiLo images, improving greatly the accuracy of the measured lifetimes. These results open the possibility of using the RLD technique with pulsed diode laser sources to determine accurately fluorescence lifetimes in the subnanosecond range on thick multilayer samples, providing that offline processing is allowed.
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Affiliation(s)
- Susana F. Silva
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - José Paulo Domingues
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Department of Physics, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - António Miguel Morgado
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Department of Physics, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
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Camborde L, Jauneau A, Brière C, Deslandes L, Dumas B, Gaulin E. Detection of nucleic acid-protein interactions in plant leaves using fluorescence lifetime imaging microscopy. Nat Protoc 2017; 12:1933-1950. [PMID: 28837131 DOI: 10.1038/nprot.2017.076] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
DNA-binding proteins (DNA-BPs) and RNA-binding proteins (RNA-BPs) have critical roles in living cells in all kingdoms of life. Various experimental approaches exist for the study of nucleic acid-protein interactions in vitro and in vivo, but the detection of such interactions at the subcellular level remains challenging. Here we describe how to detect nucleic acid-protein interactions in plant leaves by using a fluorescence resonance energy transfer (FRET) approach coupled to fluorescence lifetime imaging microscopy (FLIM). Proteins of interest (POI) are tagged with a GFP and transiently expressed in plant cells to serve as donor fluorophore. After sample fixation and cell wall permeabilization, leaves are treated with Sytox Orange, a nucleic acid dye that can function as a FRET acceptor. Upon close association of the GFP-tagged POI with Sytox-Orange-stained nucleic acids, a substantial decrease of the GFP lifetime due to FRET between the donor and the acceptor can be monitored. Treatment with RNase before FRET-FLIM measurements allows determination of whether the POI associates with DNA and/or RNA. A step-by-step protocol is provided for sample preparation, data acquisition and analysis. We describe how to calibrate the equipment and include a tutorial explaining the use of the FLIM software. To illustrate our approach, we provide experimental procedures to detect the interaction between plant DNA and two proteins (the AeCRN13 effector from the oomycete Aphanomyces euteiches and the AtWRKY22 defensive transcription factor from Arabidopsis). This protocol allows the detection of protein-nucleic acid interactions in plant cells and can be completed in <2 d.
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Affiliation(s)
- Laurent Camborde
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS-Université Toulouse, Castanet-Tolosan, France
| | - Alain Jauneau
- CNRS, Plateforme Imagerie-Microscopie, Fédération de Recherche FR3450, Castanet-Tolosan, France
| | - Christian Brière
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS-Université Toulouse, Castanet-Tolosan, France
| | - Laurent Deslandes
- LIPM, Université de Toulouse, INRA, CNRS-Université Toulouse, Castanet-Tolosan, France
| | - Bernard Dumas
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS-Université Toulouse, Castanet-Tolosan, France
| | - Elodie Gaulin
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS-Université Toulouse, Castanet-Tolosan, France
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Hinsdale T, Olsovsky C, Rico-Jimenez JJ, Maitland KC, Jo JA, Malik BH. Optically sectioned wide-field fluorescence lifetime imaging microscopy enabled by structured illumination. BIOMEDICAL OPTICS EXPRESS 2017; 8:1455-1465. [PMID: 28663841 PMCID: PMC5480556 DOI: 10.1364/boe.8.001455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/23/2017] [Accepted: 02/02/2017] [Indexed: 05/04/2023]
Abstract
In this paper, we demonstrate the ability of structured illumination microscopy to enhance the ability of fluorescence lifetime imaging to resolve fluorescence lifetimes in relatively thick samples that possess distinct but spectrally overlapping fluorescent layers. Structured illumination fluorescent lifetime imaging microscopy (SI-FLIM) is shown to be able to accurately reconstruct lifetime values in homogenous fluorophore samples (POPOP, NADH, and FAD) as well as accurately measure fluorescent lifetime in two layer models that are layered with NADH/FAD over POPOP, where NADH/FAD and POPOP have spectral overlap. Finally, the ability of SI-FLIM was demonstrated in a hamster cheek pouch ex vivo to show that more accurate lifetimes could be measured for each layer of interest in the oral mucosa (epithelium and submucosa).
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Affiliation(s)
- Taylor Hinsdale
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
| | - Cory Olsovsky
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
| | - Jose J. Rico-Jimenez
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
| | - Kristen C. Maitland
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
| | - Javier A. Jo
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
| | - Bilal H. Malik
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843, USA
- QT Ultrasound Labs, 3 Hamilton Landing, Suite 160, Novato, CA 94949, USA
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Becker W, Hirvonen LM, Milnes J, Conneely T, Jagutzki O, Netz H, Smietana S, Suhling K. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:093710. [PMID: 27782585 DOI: 10.1063/1.4962864] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ∼190 to 230 ps full width at half maximum depending on the position on the photocathode. The position of the photon event is obtained from the pulse propagation time along the two delay lines, one in x and one in y. One end of a delay line is fed into the "start" input of the corresponding TCSPC board, and the other end is delayed by 40 ns and fed into the "stop" input. The time between start and stop is directly converted into position, with a resolution of 200-250 μm. The data acquisition software builds up the distribution of the photons over their spatial coordinates, x and y, and their times after the excitation pulses, typically into 512 × 512 pixels and 1024 time channels per pixel. We apply the system to fluorescence lifetime imaging of cells labelled with Alexa 488 phalloidin in an epi-fluorescence microscope and discuss the application of our approach to other fluorescence microscopy methods.
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Affiliation(s)
- Wolfgang Becker
- Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany
| | - Liisa M Hirvonen
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - James Milnes
- Photek Ltd., 26 Castleham Rd., Saint Leonards-on-Sea TN38 9NS, United Kingdom
| | - Thomas Conneely
- Photek Ltd., 26 Castleham Rd., Saint Leonards-on-Sea TN38 9NS, United Kingdom
| | - Ottmar Jagutzki
- Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - Holger Netz
- Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany
| | - Stefan Smietana
- Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
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Křížek P, Lukeš T, Ovesný M, Fliegel K, Hagen GM. SIMToolbox: a MATLAB toolbox for structured illumination fluorescence microscopy. Bioinformatics 2015; 32:318-20. [PMID: 26446133 DOI: 10.1093/bioinformatics/btv576] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/30/2015] [Indexed: 11/14/2022] Open
Abstract
UNLABELLED SIMToolbox is an open-source, modular set of functions for MATLAB equipped with a user-friendly graphical interface and designed for processing two-dimensional and three-dimensional data acquired by structured illumination microscopy (SIM). Both optical sectioning and super-resolution applications are supported. The software is also capable of maximum a posteriori probability image estimation (MAP-SIM), an alternative method for reconstruction of structured illumination images. MAP-SIM can potentially reduce reconstruction artifacts, which commonly occur due to refractive index mismatch within the sample and to imperfections in the illumination. AVAILABILITY AND IMPLEMENTATION SIMToolbox, example data and the online documentation are freely accessible at http://mmtg.fel.cvut.cz/SIMToolbox. CONTACT ghagen@uccs.edu SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Pavel Křížek
- First Faculty of Medicine, Charles University in Prague, Prague 12800, Czech Republic
| | - Tomáš Lukeš
- Department of Radioelectronics, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague 16627, Czech Republic, Laboratoire d'Optique Biomédicale, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland and
| | - Martin Ovesný
- First Faculty of Medicine, Charles University in Prague, Prague 12800, Czech Republic
| | - Karel Fliegel
- Department of Radioelectronics, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague 16627, Czech Republic
| | - Guy M Hagen
- UCCS center for the BioFrontiers Institute, University of Colorado at Colorado Springs, Colorado Springs, CO 80918, USA
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23
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Kempema NJ, Long MB. Quantitative Rayleigh thermometry for high background scattering applications with structured laser illumination planar imaging. APPLIED OPTICS 2014; 53:6688-6697. [PMID: 25322370 DOI: 10.1364/ao.53.006688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 09/02/2014] [Indexed: 06/04/2023]
Abstract
This work demonstrates structured laser illumination planar imaging (SLIPI) for Rayleigh thermometry with high background scattering. Two coherent laser beams were crossed to produce an interference pattern, from which the modulated Rayleigh signal was collected. The modulated signal serves as a signature that identifies information about Rayleigh scattering from the probe volume against additional contributions in the image from background scattering. This work shows that the structured nature of the illumination allows for a simplified background correction. The experimental approach is validated in a non-premixed methane/air flame, and the temperature is found to be in excellent agreement with previous experimental and computational results. Rayleigh SLIPI is then applied to a high background scattering application as part of the full-field temperature measurement of sooting non-premixed ethylene/air flames. For these flames, standard Rayleigh background corrections are impossible since scattering from soot just outside the field of view is the main source of the background. Good agreement is found between SLIPI and intensity-ratio thin-filament pyrometry-derived temperature along their adjoining interface in the flame.
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24
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Implementation of transportation distance for analyzing FLIM and FRET experiments. Bull Math Biol 2014; 76:2596-626. [PMID: 25253276 DOI: 10.1007/s11538-014-0025-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
Abstract
Analysis of fluorescence lifetime imaging microscopy (FLIM) and Förster resonance energy transfer (FRET) experiments in living cells is usually based on mean lifetimes computations. However, these mean lifetimes can induce misinterpretations. We propose in this work the implementation of the transportation distance for FLIM and FRET experiments in vivo. This non-fitting indicator, which is easy to compute, reflects the similarity between two distributions and can be used for pixels clustering to improve the estimation of the FRET parameters. We study the robustness and the discriminating power of this transportation distance, both theoretically and numerically. In addition, a comparison study with the largely used mean lifetime differences is performed. We finally demonstrate practically the benefits of the transportation distance over the usual mean lifetime differences for both FLIM and FRET experiments in living cells.
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25
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Dan D, Yao B, Lei M. Structured illumination microscopy for super-resolution and optical sectioning. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11434-014-0181-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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26
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Ebrecht R, Don Paul C, Wouters FS. Fluorescence lifetime imaging microscopy in the medical sciences. PROTOPLASMA 2014; 251:293-305. [PMID: 24390249 DOI: 10.1007/s00709-013-0598-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 12/12/2013] [Indexed: 06/03/2023]
Abstract
The steady improvement in the imaging of cellular processes in living tissue over the last 10-15 years through the use of various fluorophores including organic dyes, fluorescent proteins and quantum dots, has made observing biological events common practice. Advances in imaging and recording technology have made it possible to exploit a fluorophore's fluorescence lifetime. The fluorescence lifetime is an intrinsic parameter that is unique for each fluorophore, and that is highly sensitive to its immediate environment and/or the photophysical coupling to other fluorophores by the phenomenon Förster resonance energy transfer (FRET). The fluorescence lifetime has become an important tool in the construction of optical bioassays for various cellular activities and reactions. The measurement of the fluorescence lifetime is possible in two formats; time domain or frequency domain, each with their own advantages. Fluorescence lifetime imaging applications have now progressed to a state where, besides their utility in cell biological research, they can be employed as clinical diagnostic tools. This review highlights the multitude of fluorophores, techniques and clinical applications that make use of fluorescence lifetime imaging microscopy (FLIM).
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Affiliation(s)
- René Ebrecht
- Department of Neuro- and Sensory Physiology, University Medicine Göttingen, 37073, Göttingen, Germany
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27
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Becker W, Shcheslavkiy V, Frere S, Slutsky I. Spatially resolved recording of transient fluorescence-lifetime effects by line-scanning TCSPC. Microsc Res Tech 2014; 77:216-24. [DOI: 10.1002/jemt.22331] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 12/18/2013] [Accepted: 12/18/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Wolfgang Becker
- Becker & Hickl GmbH; Nahmitzer Damm 30; 12277 Berlin Germany
| | | | - Samuel Frere
- Sackler Faculty of Medicine, Department Physiology and Pharmacology; Sagol School of Neuroscience, Tel Aviv University; Tel Aviv 69978 Israel
| | - Inna Slutsky
- Sackler Faculty of Medicine, Department Physiology and Pharmacology; Sagol School of Neuroscience, Tel Aviv University; Tel Aviv 69978 Israel
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28
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Fu HL, Mueller JL, Javid MP, Mito JK, Kirsch DG, Ramanujam N, Brown JQ. Optimization of a widefield structured illumination microscope for non-destructive assessment and quantification of nuclear features in tumor margins of a primary mouse model of sarcoma. PLoS One 2013; 8:e68868. [PMID: 23894357 PMCID: PMC3720887 DOI: 10.1371/journal.pone.0068868] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/02/2013] [Indexed: 11/25/2022] Open
Abstract
Cancer is associated with specific cellular morphological changes, such as increased nuclear size and crowding from rapidly proliferating cells. In situ tissue imaging using fluorescent stains may be useful for intraoperative detection of residual cancer in surgical tumor margins. We developed a widefield fluorescence structured illumination microscope (SIM) system with a single-shot FOV of 2.1×1.6 mm (3.4 mm2) and sub-cellular resolution (4.4 µm). The objectives of this work were to measure the relationship between illumination pattern frequency and optical sectioning strength and signal-to-noise ratio in turbid (i.e. thick) samples for selection of the optimum frequency, and to determine feasibility for detecting residual cancer on tumor resection margins, using a genetically engineered primary mouse model of sarcoma. The SIM system was tested in tissue mimicking solid phantoms with various scattering levels to determine impact of both turbidity and illumination frequency on two SIM metrics, optical section thickness and modulation depth. To demonstrate preclinical feasibility, ex vivo 50 µm frozen sections and fresh intact thick tissue samples excised from a primary mouse model of sarcoma were stained with acridine orange, which stains cell nuclei, skeletal muscle, and collagenous stroma. The cell nuclei were segmented using a high-pass filter algorithm, which allowed quantification of nuclear density. The results showed that the optimal illumination frequency was 31.7 µm−1 used in conjunction with a 4×0.1 NA objective ( = 0.165). This yielded an optical section thickness of 128 µm and an 8.9×contrast enhancement over uniform illumination. We successfully demonstrated the ability to resolve cell nuclei in situ achieved via SIM, which allowed segmentation of nuclei from heterogeneous tissues in the presence of considerable background fluorescence. Specifically, we demonstrate that optical sectioning of fresh intact thick tissues performed equivalently in regards to nuclear density quantification, to physical frozen sectioning and standard microscopy.
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Affiliation(s)
- Henry L Fu
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
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Leray A, Spriet C, Trinel D, Usson Y, Héliot L. Generalization of the polar representation in time domain fluorescence lifetime imaging microscopy for biological applications: practical implementation. J Microsc 2013; 248:66-76. [PMID: 22971219 DOI: 10.1111/j.1365-2818.2012.03651.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The polar representation or phasor, which provides a fast and visual indication on the number of exponentials present in the intensity decay of the fluorescence lifetime images is increasingly used in time domain fluorescence lifetime imaging microscopy experiments. The calculations of the polar coordinates in time domain fluorescence lifetime imaging microscopy experiments involve several experimental parameters (e.g. instrumental response function, background, angular frequency, number of temporal channels) whose role has not been exhaustively investigated. Here, we study theoretically, computationally and experimentally the influence of each parameter on the polar calculations and suggest parameter optimization for minimizing errors. We identify several sources of mistakes that may occur in the calculations of the polar coordinates and propose adapted corrections to compensate for them. For instance, we demonstrate that the numerical integration method employed for integrals calculations may induce errors when the number of temporal channels is low. We report theoretical generalized expressions to compensate for these deviations and conserve the semicircle integrity, facilitating the comparison between fluorescence lifetime imaging microscopy images acquired with distinct channels number. These theoretical generalized expressions were finally corroborated with both Monte Carlo simulations and experiments.
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Affiliation(s)
- A Leray
- Institut de Recherche Interdisciplinaire, USR 3078 CNRS, Université de Lille-Nord de France, BCF, Parc de la Haute Borne, 59650 Villeneuve d'Ascq, France.
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30
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Effect of nanoclay laponite and pH on the energy transfer between fluorescent dyes. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2012.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Křížek P, Raška I, Hagen GM. Flexible structured illumination microscope with a programmable illumination array. OPTICS EXPRESS 2012; 20:24585-24599. [PMID: 23187221 DOI: 10.1364/oe.20.024585] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Structured illumination microscopy (SIM) has grown into a family of methods which achieve optical sectioning, resolution beyond the Abbe limit, or a combination of both effects in optical microscopy. SIM techniques rely on illumination of a sample with patterns of light which must be shifted between each acquired image. The patterns are typically created with physical gratings or masks, and the final optically sectioned or high resolution image is obtained computationally after data acquisition. We used a flexible, high speed ferroelectric liquid crystal microdisplay for definition of the illumination pattern coupled with widefield detection. Focusing on optical sectioning, we developed a unique and highly accurate calibration approach which allowed us to determine a mathematical model describing the mapping of the illumination pattern from the microdisplay to the camera sensor. This is important for higher performance image processing methods such as scaled subtraction of the out of focus light, which require knowledge of the illumination pattern position in the acquired data. We evaluated the signal to noise ratio and the sectioning ability of the reconstructed images for several data processing methods and illumination patterns with a wide range of spatial frequencies. We present our results on a thin fluorescent layer sample and also on biological samples, where we achieved thinner optical sections than either confocal laser scanning or spinning disk microscopes.
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Affiliation(s)
- Pavel Křížek
- Charles University in Prague, First Faculty of Medicine, Institute of Cellular Biology and Pathology, Prague, Czech Republic
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32
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Li L, Zhao JF, Won N, Jin H, Kim S, Chen JY. Quantum dot-aluminum phthalocyanine conjugates perform photodynamic reactions to kill cancer cells via fluorescence resonance energy transfer. NANOSCALE RESEARCH LETTERS 2012; 7:386. [PMID: 22784858 PMCID: PMC3651390 DOI: 10.1186/1556-276x-7-386] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 06/22/2012] [Indexed: 05/25/2023]
Abstract
Sulfonated aluminum phthalocyanines (AlPcSs), commonly used photosensitizers for photodynamic therapy of cancers (PDT), were conjugated with amine-dihydrolipoic acid-coated quantum dots (QDs) by electrostatic binding, achieving 70 AlPcSs per QD. The AlPcS-QD conjugates can utilize the intense light absorptions of conjugated QDs to indirectly excite AlPcSs producing singlet oxygen via fluorescence resonance energy transfer (FRET), demonstrating a new excitation model for PDT. The AlPcS-QD conjugates easily penetrated into human nasopharyngeal carcinoma cells and carried out the FRET in cells, with efficiency around 80%. Under the irradiation of a 532-nm laser, which is at the absorption region of QDs but not fit for the absorption of AlPcSs, the cellular AlPcS-QD conjugates can destroy most cancer cells via FRET-mediated PDT, showing the potential of this new strategy for PDT.
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Affiliation(s)
- Lei Li
- State Key Laboratory of Surface Physics, Department of Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai,, 200433, People's Republic of China
| | - Jin-Feng Zhao
- State Key Laboratory of Surface Physics, Department of Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai,, 200433, People's Republic of China
| | - Nayoun Won
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Nam-Gu, Pohang, Gyeong-Buk,, 790-784, South Korea
| | - Ho Jin
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Nam-Gu, Pohang, Gyeong-Buk,, 790-784, South Korea
| | - Sungjee Kim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Nam-Gu, Pohang, Gyeong-Buk,, 790-784, South Korea
| | - Ji-Yao Chen
- State Key Laboratory of Surface Physics, Department of Physics, and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai,, 200433, People's Republic of China
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Auksorius E, Bromberg Y, Motiejūnaitė R, Pieretti A, Liu L, Coron E, Aranda J, Goldstein AM, Bouma BE, Kazlauskas A, Tearney GJ. Dual-modality fluorescence and full-field optical coherence microscopy for biomedical imaging applications. BIOMEDICAL OPTICS EXPRESS 2012; 3:661-6. [PMID: 22435110 PMCID: PMC3296550 DOI: 10.1364/boe.3.000661] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 02/17/2012] [Accepted: 02/24/2012] [Indexed: 05/21/2023]
Abstract
Full-field optical coherence microscopy (FFOCM) is a high-resolution interferometric technique that is particularly attractive for biomedical imaging. Here we show that combining it with structured illumination fluorescence microscopy on one platform can increase its versatility since it enables co-localized registration of optically sectioned reflectance and fluorescence images. To demonstrate the potential of this dual modality, a fixed and labeled mouse retina was imaged. Results showed that both techniques can provide complementary information and therefore the system could potentially be useful for biomedical imaging applications.
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Affiliation(s)
- Egidijus Auksorius
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Yaron Bromberg
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Rūta Motiejūnaitė
- Harvard Medical School and Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, 20 Staniford Street, Boston, MA 02114, USA
- Department of Biochemistry and Biophysics, Vilnius University, Vilnius, Lithuania
| | - Alberto Pieretti
- Department of Pediatric Surgery, Harvard Medical School and Massachusetts General Hospital, Boston, MA 02114, USA
| | - Linbo Liu
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Emmanuel Coron
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Jorge Aranda
- Harvard Medical School and Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, 20 Staniford Street, Boston, MA 02114, USA
| | - Allan M. Goldstein
- Department of Pediatric Surgery, Harvard Medical School and Massachusetts General Hospital, Boston, MA 02114, USA
| | - Brett E. Bouma
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Andrius Kazlauskas
- Harvard Medical School and Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, 20 Staniford Street, Boston, MA 02114, USA
| | - Guillermo J. Tearney
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
- Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Department of Pathology, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
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35
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Wu Q, Guo S, Ma Y, Gao F, Yang C, Yang M, Yu X, Zhang X, Rupp RA, Xu J. Optical refocusing three-dimensional wide-field fluorescence lifetime imaging microscopy. OPTICS EXPRESS 2012; 20:960-965. [PMID: 22274443 DOI: 10.1364/oe.20.000960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Three-dimensional fluorescence lifetime microscopy is achieved by combining wide-field fluorescence lifetime imaging with a remote optical refocusing method. As required for some applications in dynamic research for physics, chemistry, or biology, it is thereby not necessary to move the sample, i.e., the specimen is not disturbed during measurement. Using a fluorescent microsphere the performance of the system has been tested successfully with respect to three-dimensional fluorescence lifetime microscopy as well as time-resolved fluorescence spectroscopy.
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Affiliation(s)
- Qiang Wu
- The MOE Key Laboratory of Weak Light Nonlinear Photonics, TEDA Applied Physics School and School of Physics, Nankai University, Tianjin, China
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36
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Hagen N, Gao L, Tkaczyk TS. Quantitative sectioning and noise analysis for structured illumination microscopy. OPTICS EXPRESS 2012; 20:403-13. [PMID: 22274364 PMCID: PMC3336372 DOI: 10.1364/oe.20.000403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Structured illumination (SI) has long been regarded as a nonquantitative technique for obtaining sectioned microscopic images. Its lack of quantitative results has restricted the use of SI sectioning to qualitative imaging experiments, and has also limited researchers' ability to compare SI against competing sectioning methods such as confocal microscopy. We show how to modify the standard SI sectioning algorithm to make the technique quantitative, and provide formulas for calculating the noise in the sectioned images. The results indicate that, for an illumination source providing the same spatially-integrated photon flux at the object plane, and for the same effective slice thicknesses, SI sectioning can provide higher SNR images than confocal microscopy for an equivalent setup when the modulation contrast exceeds about 0.09.
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Affiliation(s)
- Nathan Hagen
- Department of Bioengineering, Rice University, Houston, Texas 77005,
USA
| | - Liang Gao
- Department of Bioengineering, Rice University, Houston, Texas 77005,
USA
| | - Tomasz S. Tkaczyk
- Department of Bioengineering, Rice University, Houston, Texas 77005,
USA
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37
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Murray JM. Methods for imaging thick specimens: confocal microscopy, deconvolution, and structured illumination. Cold Spring Harb Protoc 2011; 2011:1399-437. [PMID: 22135661 DOI: 10.1101/pdb.top066936] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
When a thick specimen is viewed through a conventional microscope, one sees the sum of a sharp image of an in-focus region plus blurred images of all of the out-of-focus regions. High background, scattering, and aberrations are all problems when viewing thick specimens. Several methods are available to deal with these problems in living samples. These methods can be grouped into three classes: primarily optical (e.g., confocal microscopy, multiphoton microscopy), primarily computational (e.g., deconvolution techniques), and mixed (e.g., structured illumination) approaches. This article describes these techniques, which make it possible to see details within thick specimens (e.g., the interiors of cells within living tissue) by optical sectioning, without the artifacts associated with physically sectioning the specimen.
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38
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Kristensson E, Araneo L, Berrocal E, Manin J, Richter M, Aldén M, Linne M. Analysis of multiple scattering suppression using structured laser illumination planar imaging in scattering and fluorescing media. OPTICS EXPRESS 2011; 19:13647-13663. [PMID: 21747521 DOI: 10.1364/oe.19.013647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The accuracy, precision and limitations of the imaging technique named Structured Laser Illumination Planar Imaging (SLIPI) have been investigated. SLIPI, which allows multiply scattered light to be diminished, has previously demonstrated improvements in image quality and contrast for spray imaging. In the current study the method is applied to a controlled confined environment consisting of a mixture of water and monodisperse polystyrene microspheres. Elastic scattering and fluorescence are studied and the results obtained when probing different particle concentrations and diameters conclusively show the advantages of SLIPI for imaging within moderately turbid media. Although the technique presents both good repeatability and agreement with the Beer-Lambert law, discrepancies in its performance were, however, discovered. Photons undergoing scattering without changing their incident trajectory cannot be discriminated and, owing to differences in scattering phase functions, probing larger particles reduces the suppression of multiply scattered light. However, in terms of visibility such behavior is beneficial as it allows denser media to be probed. It is further demonstrated that the suppression of diffuse light performs equally well regardless of whether photons propagate along the incident direction or towards the camera. In addition, this filtering process acts independently on the spatial distribution of the multiply scattered light but is limited by the finite dynamic range and unavoidable signal noise of the camera.
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Affiliation(s)
- E Kristensson
- Division of Combustion Physics, Lund Institute of Technology, Lund University, Lund, Sweden.
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39
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Hussain SA, Chakraborty S, Bhattacharjee D, Schoonheydt RA. Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir-Blodgett (LB) films. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:664-670. [PMID: 20018558 DOI: 10.1016/j.saa.2009.11.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 11/12/2009] [Accepted: 11/17/2009] [Indexed: 05/28/2023]
Abstract
In this communication we investigate two dyes N,N'-dioctadecyl thiacyanine perchlorate (NK) and octadecyl rhodamine B chloride (RhB) in Langmuir and Langmuir-Blodgett (LB) films with or with out a synthetic clay laponite. Observed changes in isotherms of RhB in absence and presence of nano-clay platelets indicate the incorporation of clay platelets onto RhB-clay hybrid films. AFM images confirm the incorporation of clay into hybrid films. FRET is observed in clay dispersion and LB films with and without clay. Efficiency of energy transfer is maximum in LB films with clay.
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Affiliation(s)
- Syed Arshad Hussain
- Department of Physics, Tripura University, Suryamaninagar 799130, Tripura, India.
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40
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Petrášek Z, Eckert HJ, Kemnitz K. Wide-field photon counting fluorescence lifetime imaging microscopy: application to photosynthesizing systems. PHOTOSYNTHESIS RESEARCH 2009; 102:157-168. [PMID: 19533411 DOI: 10.1007/s11120-009-9444-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 05/19/2009] [Indexed: 05/27/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is a technique that visualizes the excited state kinetics of fluorescence molecules with the spatial resolution of a fluorescence microscope. We present a scanningless implementation of FLIM based on a time- and spacecorrelated single photon counting (TSCSPC) method employing a position-sensitive quadrant anode detector and wide-field illumination. The standard time-correlated photon counting approach leads to picosecond temporal resolution, making it possible to resolve complex fluorescence decays. This allows parallel acquisition of time-resolved images of biological samples under minimally invasive low-excitation conditions (<10 mW/cm(2)). In this way unwanted photochemical reactions induced by high excitation intensities and distorting the decay kinetics are avoided. Comparably low excitation intensities are practically impossible to achieve with a conventional laser scanning microscope, where focusing of the excitation beam into a tight spot is required. Therefore, wide-field FLIM permits to study Photosystem II (PS II) in a way so far not possible with a laser scanning microscope. The potential of the wide-field TSCSPC method is demonstrated by presenting FLIM measurements of the fluorescence dynamics of photosynthetic systems in living cells of the chlorophyll d-containing cyanobacterium Acaryochloris marina.
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Affiliation(s)
- Zdeněk Petrášek
- Biophysics group, Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47-51, 01307 Dresden, Germany
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41
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Langhorst MF, Schaffer J, Goetze B. Structure brings clarity: structured illumination microscopy in cell biology. Biotechnol J 2009; 4:858-65. [PMID: 19492328 DOI: 10.1002/biot.200900025] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Biological samples are three dimensional and, therefore, optical sectioning is mandatory for microscopic images to precisely show the localization or function of structures within biological samples. Today, researchers can choose from a variety of methods to obtain optical sections. This article focuses on structured illumination microscopy, which is a group of techniques utilizing a combination of optics and mathematics to obtain optical sections: A structure is imaged onto the sample by optical means and the additional information thereby encoded in the image is used to calculate an optical section from several acquired images. Different methods of structured illumination microscopy (mainly grid projection and aperture correlation) are discussed from a practical point of view, concentrating on advantages, limitations and future prospects of these techniques and their use in cell biology. Structured illumination can also be used to obtain super-resolution information if structures of higher frequency are projected onto the sample. This promising approach to super-resolution microscopy is also briefly discussed from a user's perspective.
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42
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Leray A, Riquet FB, Richard E, Spriet C, Trinel D, Héliot L. Optimized protocol of a frequency domain fluorescence lifetime imaging microscope for FRET measurements. Microsc Res Tech 2009; 72:371-9. [DOI: 10.1002/jemt.20665] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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43
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Weigel A, Schild D, Zeug A. Resolution in the ApoTome and the confocal laser scanning microscope: comparison. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:014022. [PMID: 19256710 DOI: 10.1117/1.3083439] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The essential feature of the confocal laser scanning microscope (cLSM) is the generation of optical sections by the removal of out-of-focus light. About ten years ago, structured illumination microscopy (SIM) was introduced as an alternative method for obtaining optical sections from biological specimens. Here we compare the resolution of the ApoTome (commercial SIM by Zeiss) to that achieved by a cLSM (Zeiss LSM 510). If fluorescent beads are used as test objects, then the ApoTome will achieve a lower axial resolution than the cLSM. In contrast to that, its lateral resolution scores slightly better. If subresolution homogeneous fluorescent layers are used as test objects, then the ApoTome will achieve a higher axial resolution than the cLSM. The ApoTome's axial resolution is homogeneous over the field-of-view while that of the cLSM changes markedly. Finally, the anisotropy of the ApoTome's resolution was found to be negligible for standard applications while its capability to resolve fine structures within stained tissue slices is limited to one or two cell layers and thus worse than in the cLSM.
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Affiliation(s)
- Arwed Weigel
- University of Gottingen, Department of Neurophysiology and Cellular Biophysics, Humboldtallee 23, 37073 Gottingen, Germany
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44
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Sud D, Mycek MA. Image restoration for fluorescence lifetime imaging microscopy (FLIM). OPTICS EXPRESS 2008; 16:19192-19200. [PMID: 19582011 DOI: 10.1364/oe.16.019192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Computational image restoration finds wide applicability for fluorescence intensity imaging. Relatively little work in this regard has been performed on FLIM images, which also suffer from diminished spatial resolution. In this work, we report two separate approaches to enhance FLIM image quality while maintaining lifetime accuracy. A 2D-image restoration algorithm was employed to improve resolution in gated intensity images of various samples including fluorescent beads, living cells and fixed tissue samples. The restoration approach improved lifetime image quality without significant variation in lifetime. Further, overlaying a restored-intensity image over the native lifetime image provided even better results, where the resulting lifetime map had spatial features similar to the intensity map. 2D and 3D image restoration also benefit from advances in computational power and hence holds potential for enhancing FLIM resolution, particularly in ICCD-based wide-field FLIM systems, without sacrificing vital quantitative information.
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Affiliation(s)
- Dhruv Sud
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2099, USA
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45
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Kristensson E, Richter M, Pettersson SG, Aldén M, Andersson-Engels S. Spatially resolved, single-ended two-dimensional visualization of gas flow phenomena using structured illumination. APPLIED OPTICS 2008; 47:3927-3931. [PMID: 18641763 DOI: 10.1364/ao.47.003927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A method for 3D mapping of scattering particle concentration in a gaseous medium based on the backscattered light in a single direction has been demonstrated. The technique is originally developed for microscopy but now implemented on larger-scale samples. The technique used is known as structured illumination, where a sinusoidal grid pattern is projected onto the medium, thus marking the in-focus plane. This makes it possible to discriminate against light originating from the out-of-focus parts of the sample, which usually makes it difficult to detect inner structures of the medium. In this study a flow of nitrogen was introduced into a flow of water droplets, with the aim to optically select only the plane where nitrogen was present. The results indicate that the technique could be used to study, e.g., combustion devices with limited optical access.
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Affiliation(s)
- Elias Kristensson
- Division of Combustion Physics, Lund Institute of Technology, Box 118, S-221 00, Lund, Sweden. elias@
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46
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Bednarkiewicz A, Whelan MP. Global analysis of microscopic fluorescence lifetime images using spectral segmentation and a digital micromirror spatial illuminator. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:041316. [PMID: 19021324 DOI: 10.1117/1.2950308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Fluorescence lifetime imaging (FLIM) is very demanding from a technical and computational perspective, and the output is usually a compromise between acquisition/processing time and data accuracy and precision. We present a new approach to acquisition, analysis, and reconstruction of microscopic FLIM images by employing a digital micromirror device (DMD) as a spatial illuminator. In the first step, the whole field fluorescence image is collected by a color charge-coupled device (CCD) camera. Further qualitative spectral analysis and sample segmentation are performed to spatially distinguish between spectrally different regions on the sample. Next, the fluorescence of the sample is excited segment by segment, and fluorescence lifetimes are acquired with a photon counting technique. FLIM image reconstruction is performed by either raster scanning the sample or by directly accessing specific regions of interest. The unique features of the DMD illuminator allow the rapid on-line measurement of global good initial parameters (GIP), which are supplied to the first iteration of the fitting algorithm. As a consequence, a decrease of the computation time required to obtain a satisfactory quality-of-fit is achieved without compromising the accuracy and precision of the lifetime measurements.
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Affiliation(s)
- Artur Bednarkiewicz
- European Commission Joint Research Center, Institute of Health and Customer Protection, T.P.202 Via E. Fermi 2749, I-21027 Ispra (VA), Italy.
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47
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Bozinovic N, Ventalon C, Ford T, Mertz J. Fluorescence endomicroscopy with structured illumination. OPTICS EXPRESS 2008; 16:8016-25. [PMID: 18545511 DOI: 10.1364/oe.16.008016] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present an endomicroscope apparatus that utilizes structured illumination to produce high resolution (approximately 2.6 microm) optically sectioned fluorescence images over a field of view of about 240 microm. The endomicroscope is based on the use of a flexible imaging fiber bundle with a miniaturized objective. We also present a strategy to largely suppress structured illumination artifacts that arise when imaging in thick tissue that exhibits significant out-of-focus background. To establish the potential of our endomicroscope for preclinical or clinical applications, we provide images of BCECF-AM labeled rat colonic mucosa.
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Affiliation(s)
- Nenad Bozinovic
- Department of Biomedical Engineering, Boston University, 44 Cummington St., Boston, MA 02215, USA.
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48
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Sahare PD, Sharma VK, Mohan D, Rupasov AA. Energy transfer studies in binary dye solution mixtures: Acriflavine+Rhodamine 6G and Acriflavine+Rhodamine B. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 69:1257-64. [PMID: 17765006 DOI: 10.1016/j.saa.2007.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Revised: 03/28/2007] [Accepted: 07/03/2007] [Indexed: 05/17/2023]
Abstract
The effect of acceptor concentration on the energy transfer in Acriflavine (donar) plus Rhodamine 6G (Rh 6G) and Acriflavine plus Rhodamine B (Rh B) binary solution mixtures has been studied. The theoretical calculations are done to determine their lifetimes. Effect of these values on the total transfer efficiency at various acceptor concentrations have been studied to identify the appropriate energy transfer mechanism responsible for photon emissions, enhancement in lasing efficiency and dreading of the tenability of such mixed solutions. The energy transfer rate constants and critical transfer radius (R(0)) are calculated using Stern-Volmer plots and concentration dependence of radiative and non-radiative transfer efficiencies have also been determined. The experimental results indicate that dominant mechanism responsible for the efficient energy transfer in the binary mixtures is of non-radiative kind and is due to long-range dipole-dipole interaction.
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Affiliation(s)
- P D Sahare
- Department of Physics, University of Pune, Pune 411007, India.
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49
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Jones PB, Rozkalne A, Meyer-Luehmann M, Spires-Jones TL, Makarova A, Kumar ATN, Berezovska O, Bacskai BB, Hyman BT. Two postprocessing techniques for the elimination of background autofluorescence for fluorescence lifetime imaging microscopy. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:014008. [PMID: 18315366 DOI: 10.1117/1.2837169] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The analysis of fluorescence lifetime imaging microscopy (FLIM) data under complex biological conditions can be challenging. Particularly, the presence of short-lived autofluorescent aggregates can confound lifetime measurements in fluorescence energy transfer (FRET) experiments, where it can become confused with the signal from exogenous fluorophores. Here we report two techniques that can be used to discriminate the contribution of autofluorescence from exogenous fluorphores in FLIM. We apply the techniques to transgenic mice that natively express yellow fluorescence protein (YFP) in a subset of cortical neurons and to histological slices of aged human brain tissue, where we study the misfolding of intracellular tau protein in the form of neurofibrillary tangles.
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Affiliation(s)
- Phillip B Jones
- Harvard Medical School, Massachusetts General Hospital, MassGeneral Institute for Neurodegenerative Disorders, 114 16th Street, Charlestown, Massachusetts 02129, USA
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50
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Breuninger T, Greger K, Stelzer EHK. Lateral modulation boosts image quality in single plane illumination fluorescence microscopy. OPTICS LETTERS 2007; 32:1938-40. [PMID: 17603620 DOI: 10.1364/ol.32.001938] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A new microscope combines optical sectioning by fluorophore excitation using a single light sheet with structured illumination. Several images with laterally intensity-modulated light sheets are recorded from scattering fluorescent specimens. By applying a simple data processing scheme, the nonmodulated volumes are identified. The blurred features become dark, and the resultant images are improved in terms of contrast and resolution. Hence, the instrument is capable of discriminating against contributions to the image that are induced by the optical properties of the specimen. The new microscope's capabilities are demonstrated by imaging the internals of the head of an adult Drosophila melanogaster (fruit fly) expressing green fluorescent protein-labeled polycomb proteins.
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Affiliation(s)
- Tobias Breuninger
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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