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Mai H, Jarman A, Erdogan AT, Treacy C, Finlayson N, Henderson RK, Poland SP. Development of a high-speed line-scanning fluorescence lifetime imaging microscope for biological imaging. OPTICS LETTERS 2023; 48:2042-2045. [PMID: 37058637 DOI: 10.1364/ol.482403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/25/2023] [Indexed: 06/19/2023]
Abstract
We report the development of a novel line-scanning microscope capable of acquiring high-speed time-correlated single-photon counting (TCSPC)-based fluorescence lifetime imaging microscopy (FLIM) imaging. The system consists of a laser-line focus, which is optically conjugated to a 1024 × 8 single-photon avalanche diode (SPAD)-based line-imaging complementary metal-oxide semiconductor (CMOS), with 23.78 µm pixel pitch at 49.31% fill factor. Incorporation of on-chip histogramming on the line-sensor enables acquisition rates 33 times faster than our previously reported bespoke high-speed FLIM platforms. We demonstrate the imaging capability of the high-speed FLIM platform in a number of biological applications.
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2
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Bowman AJ, Kasevich MA. Resonant Electro-Optic Imaging for Microscopy at Nanosecond Resolution. ACS NANO 2021; 15:16043-16054. [PMID: 34546704 DOI: 10.1021/acsnano.1c04470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We demonstrate an electro-optic wide-field method to enable fluorescence lifetime microscopy (FLIM) with high throughput and single-molecule sensitivity. Resonantly driven Pockels cells are used to efficiently gate images at 39 MHz, allowing fluorescence lifetime to be captured on standard camera sensors. Lifetime imaging of single molecules is enabled in wide field with exposure times of less than 100 ms. This capability allows combination of wide-field FLIM with single-molecule super-resolution localization microscopy. Fast single-molecule dynamics such as FRET and molecular binding events are captured from wide-field images without prior spatial knowledge. A lifetime sensitivity of 1.9 times the photon shot-noise limit is achieved, and high throughput is shown by acquiring wide-field FLIM images with millisecond exposure and >108 photons per frame. Resonant electro-optic FLIM allows lifetime contrast in any wide-field microscopy method.
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Affiliation(s)
- Adam J Bowman
- Physics Department, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305, United States
| | - Mark A Kasevich
- Physics Department, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305, United States
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3
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Trinh AL, Esposito A. Biochemical resolving power of fluorescence lifetime imaging: untangling the roles of the instrument response function and photon-statistics. BIOMEDICAL OPTICS EXPRESS 2021; 12:3775-3788. [PMID: 34457379 PMCID: PMC8367261 DOI: 10.1364/boe.428070] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/21/2021] [Accepted: 05/28/2021] [Indexed: 05/29/2023]
Abstract
A deeper understanding of spatial resolution has led to innovations in microscopy and the disruption of biomedical research, as with super-resolution microscopy. To foster similar advances in time-resolved and spectral imaging, we have previously introduced the concept of 'biochemical resolving power' in fluorescence microscopy. Here, we apply those concepts to investigate how the instrument response function (IRF), sampling conditions, and photon-statistics limit the biochemical resolution of fluorescence lifetime microscopy. Using Fisher information analysis and Monte Carlo simulations, we reveal the complex dependencies between photon-statistics and the IRF, permitting us to quantify resolution limits that have been poorly understood (e.g., the minimum resolvable decay time for a given width of the IRF and photon-statistics) or previously underappreciated (e.g., optimization of the IRF for biochemical detection). With this work, we unravel common misunderstandings on the role of the IRF and provide theoretical insights with significant practical implications on the design and use of time-resolved instrumentation.
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Affiliation(s)
- Andrew L Trinh
- MRC Cancer Unit, University of Cambridge, Cambridge, United Kingdom
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4
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Tavakoli M, Jazani S, Sgouralis I, Heo W, Ishii K, Tahara T, Pressé S. Direct Photon-by-Photon Analysis of Time-Resolved Pulsed Excitation Data using Bayesian Nonparametrics. CELL REPORTS. PHYSICAL SCIENCE 2020; 1:100234. [PMID: 34414380 PMCID: PMC8373049 DOI: 10.1016/j.xcrp.2020.100234] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Lifetimes of chemical species are typically estimated by either fitting time-correlated single-photon counting (TCSPC) histograms or phasor analysis from time-resolved photon arrivals. While both methods yield lifetimes in a computationally efficient manner, their performance is limited by choices made on the number of distinct chemical species contributing photons. However, the number of species is encoded in the photon arrival times collected for each illuminated spot and need not be set by hand a priori. Here, we propose a direct photon-by-photon analysis of data drawn from pulsed excitation experiments to infer, simultaneously and self-consistently, the number of species and their associated lifetimes from a few thousand photons. We do so by leveraging new mathematical tools within the Bayesian nonparametric. We benchmark our method for both simulated and experimental data for 1-4 species.
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Affiliation(s)
- Meysam Tavakoli
- Department of Physics, Indiana University-Purdue University, Indianapolis, IN 46202, USA
| | - Sina Jazani
- Center for Biological Physics, Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Ioannis Sgouralis
- Center for Biological Physics, Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Wooseok Heo
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kunihiko Ishii
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Steve Pressé
- Center for Biological Physics, Department of Physics, Arizona State University, Tempe, AZ 85287, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
- Lead Contact
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5
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Hirvonen LM, Nedbal J, Almutairi N, Phillips TA, Becker W, Conneely T, Milnes J, Cox S, Stürzenbaum S, Suhling K. Lightsheet fluorescence lifetime imaging microscopy with wide-field time-correlated single photon counting. JOURNAL OF BIOPHOTONICS 2020; 13:e201960099. [PMID: 31661595 PMCID: PMC7065631 DOI: 10.1002/jbio.201960099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/21/2019] [Accepted: 10/24/2019] [Indexed: 05/22/2023]
Abstract
We report on wide-field time-correlated single photon counting (TCSPC)-based fluorescence lifetime imaging microscopy (FLIM) with lightsheet illumination. A pulsed diode laser is used for excitation, and a crossed delay line anode image intensifier, effectively a single-photon sensitive camera, is used to record the position and arrival time of the photons with picosecond time resolution, combining low illumination intensity of microwatts with wide-field data collection. We pair this detector with the lightsheet illumination technique, and apply it to 3D FLIM imaging of dye gradients in human cancer cell spheroids, and C. elegans.
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Affiliation(s)
- Liisa M. Hirvonen
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Jakub Nedbal
- Department of PhysicsKing's College LondonLondonUK
| | - Norah Almutairi
- School of Population Health & Environmental Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
| | - Thomas A. Phillips
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | | | | | | | - Susan Cox
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Stephen Stürzenbaum
- School of Population Health & Environmental Sciences, Faculty of Life Sciences & MedicineKing's College LondonLondonUK
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6
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Esposito A. How many photons are needed for FRET imaging? BIOMEDICAL OPTICS EXPRESS 2020; 11:1186-1202. [PMID: 32133242 PMCID: PMC7041441 DOI: 10.1364/boe.379305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/15/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
Förster resonance energy transfer (FRET) imaging is an essential analytical method in biomedical research. The limited photon-budget experimentally available, however, imposes compromises between spatiotemporal and biochemical resolutions, photodamage and phototoxicity. The study of photon-statistics in biochemical imaging is thus important in guiding the efficient design of instrumentation and assays. Here, we show a comparative analysis of photon-statistics in FRET imaging demonstrating how the precision of FRET imaging varies vastly with imaging parameters. Therefore, we provide analytical and numerical tools for assay optimization. Fluorescence lifetime imaging microscopy (FLIM) is a very robust technique with excellent photon-efficiencies. However, we show that also intensity-based FRET imaging can reach high precision by utilizing information from both donor and acceptor fluorophores.
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Affiliation(s)
- Alessandro Esposito
- MRC Cancer Unit, University of Cambridge, Biomedical Campus, Cambridge, CB20XY, UK
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7
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Suhling K, Hirvonen LM, Becker W, Smietana S, Netz H, Milnes J, Conneely T, Marois AL, Jagutzki O, Festy F, Petrášek Z, Beeby A. Wide-field time-correlated single photon counting-based fluorescence lifetime imaging microscopy. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT 2019; 942:162365. [PMID: 31645797 PMCID: PMC6716551 DOI: 10.1016/j.nima.2019.162365] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 05/23/2023]
Abstract
Wide-field time-correlated single photon counting detection techniques, where the position and the arrival time of the photons are recorded simultaneously using a camera, have made some advances recently. The technology and instrumentation used for this approach is employed in areas such as nuclear science, mass spectroscopy and positron emission tomography, but here, we discuss some of the wide-field TCSPC methods, for applications in fluorescence microscopy. We describe work by us and others as presented in the Ulitima fast imaging and tracking conference at the Argonne National Laboratory in September 2018, from phosphorescence lifetime imaging (PLIM) microscopy on the microsecond time scale to fluorescence lifetime imaging (FLIM) on the nanosecond time scale, and highlight some applications of these techniques.
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Affiliation(s)
- Klaus Suhling
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
- Corresponding author.
| | - Liisa M. Hirvonen
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Wolfgang Becker
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - Stefan Smietana
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - Holger Netz
- Becker & Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany
| | - James Milnes
- Photek Ltd, 26 Castleham Rd, St Leonards on Sea TN38 9NS, UK
| | - Thomas Conneely
- Photek Ltd, 26 Castleham Rd, St Leonards on Sea TN38 9NS, UK
| | - Alix Le Marois
- Department of Physics, King’s College London, Strand, London WC2R 2LS, UK
| | - Ottmar Jagutzki
- Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany
| | - Fred Festy
- Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guys Hospital, Kings Health Partners, Guys Dental Hospital, London Bridge, London SE1 9RT, UK
| | - Zdeněk Petrášek
- Institut für Biotechnologie und Bioprozesstechnik, Technische Universität Graz, Petersgasse, 10-12/I, 8010 Graz, Austria
| | - Andrew Beeby
- Department of Chemistry, University of Durham, Durham DH13LE, UK
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8
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Electro-optic imaging enables efficient wide-field fluorescence lifetime microscopy. Nat Commun 2019; 10:4561. [PMID: 31594938 PMCID: PMC6783475 DOI: 10.1038/s41467-019-12535-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022] Open
Abstract
Nanosecond temporal resolution enables new methods for wide-field imaging like time-of-flight, gated detection, and fluorescence lifetime. The optical efficiency of existing approaches, however, presents challenges for low-light applications common to fluorescence microscopy and single-molecule imaging. We demonstrate the use of Pockels cells for wide-field image gating with nanosecond temporal resolution and high photon collection efficiency. Two temporal frames are obtained by combining a Pockels cell with a pair of polarizing beam-splitters. We show multi-label fluorescence lifetime imaging microscopy (FLIM), single-molecule lifetime spectroscopy, and fast single-frame FLIM at the camera frame rate with 103–105 times higher throughput than single photon counting. Finally, we demonstrate a space-to-time image multiplexer using a re-imaging optical cavity with a tilted mirror to extend the Pockels cell technique to multiple temporal frames. These methods enable nanosecond imaging with standard optical systems and sensors, opening a new temporal dimension for wide-field low-light microscopy. Nanosecond imaging techniques, such as fluorescence lifetime imaging microscopy (FLIM), are limited by low efficiency of current detectors. Here, the authors implement an electro-optic approach using Pockels cells for wide-field image gating and demonstrate high throughput FLIM on standard camera sensors.
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Trinh AL, Ber S, Howitt A, Valls PO, Fries MW, Venkitaraman AR, Esposito A. Fast single-cell biochemistry: theory, open source microscopy and applications. Methods Appl Fluoresc 2019; 7:044001. [PMID: 31422954 PMCID: PMC7000240 DOI: 10.1088/2050-6120/ab3bd2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fluorescence lifetime sensing enables researchers to probe the physicochemical environment of a fluorophore providing a window through which we can observe the complex molecular make-up of the cell. Fluorescence lifetime imaging microscopy (FLIM) quantifies and maps cell biochemistry, a complex ensemble of dynamic processes. Unfortunately, typical high-resolution FLIM systems exhibit rather limited acquisition speeds, often insufficient to capture the time evolution of biochemical processes in living cells. Here, we describe the theoretical background that justifies the developments of high-speed single photon counting systems. We show that systems with low dead-times not only result in faster acquisition throughputs but also improved dynamic range and spatial resolution. We also share the implementation of hardware and software as an open platform, show applications of fast FLIM biochemical imaging on living cells and discuss strategies to balance precision and accuracy in FLIM. The recent innovations and commercialisation of fast time-domain FLIM systems are likely to popularise FLIM within the biomedical community, to impact biomedical research positively and to foster the adoption of other FLIM techniques as well. While supporting and indeed pursuing these developments, with this work we also aim to warn the community about the possible shortcomings of fast single photon counting techniques and to highlight strategies to acquire data of high quality.
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10
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Aluko J, Perrin C, Devauges V, Nedbal J, Poland S, Matthews D, Whittaker J, Ameer-Beg S. Semi-autonomous real-time programmable fluorescence lifetime segmentation with a digital micromirror device. OPTICS EXPRESS 2018; 26:31055-31074. [PMID: 30650697 DOI: 10.1364/oe.26.031055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 08/22/2018] [Indexed: 06/09/2023]
Abstract
Time-correlated single-photon counting (TCSPC) is the gold standard for performing lifetime spectroscopy in biological assays. Traditional fluorescence lifetime imaging (FLIM) using laser scanning microscopes are inherently slow due to point scanning all pixels in the field-of-view. Wide-field implementations of TCSPC spectroscopy using microchannel plates benefit from particularly fast acquisition times at the expense of temporal resolution, and are fundamentally limited by photon counting rates. Here, we introduce programmable lifetime imaging (PLI), combining the advantages of wide-field imaging using total internal reflection excitation with state-of-the-art TCSPC detector technology for accurate lifetime determination in an object-oriented manner using a digital micromirror device (DMD). The fluorescent emission is projected onto the DMD to facilitate the sequential segmentation of fluorescence from individual objects in the field-of-view, allowing for both image acquisition and fluorescence lifetime determination of the assay. The sensitivity of PLI is demonstrated by manually segmenting fluorescence from fixed cell assays. We also demonstrate an automated implementation of PLI, using a camera as a feedback mechanism to segment fluorescence produced by emitting objects of interest in the imaging field-of-view, highlighting the advantages of measurement only in areas where valuable information exists. As a result, PLI is able to reduce acquisition time of fluorescence lifetime data by at least an order of magnitude compared to laser scanning implementations.
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11
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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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12
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Yahav G, Barnoy E, Roth N, Turgeman L, Fixler D. Reference-independent wide field fluorescence lifetime measurements using Frequency-Domain (FD) technique based on phase and amplitude crossing point. JOURNAL OF BIOPHOTONICS 2017; 10:1198-1207. [PMID: 27774782 DOI: 10.1002/jbio.201600220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/29/2016] [Accepted: 09/30/2016] [Indexed: 06/06/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is an essential tool in many scientific fields such as biology and medicine thanks to the known advantages of the fluorescence lifetime (FLT) over the classical fluorescence intensity (FI). However, the frequency domain (FD) FLIM technique suffers from its strong dependence on the reference and its compliance to the sample. In this paper, we suggest a new way to calculate the FLT by using the crossing point (CRPO) between the modulation and phase FLTs measured over several light emitting diode (LED) DC currents values instead of either method alone. This new technique was validated by measuring homogeneous substances with known FLT, where the CRPO appears to be the optimal measuring point. Furthermore, the CRPO method was applied in heterogeneous samples. It was found that the CRPO in known mixed solutions is the weighted average of the used solutions. While measuring B16 and lymphocyte cells, the CRPO of the DAPI compound in single FLT regions was measured at 3.5 ± 0.06 ns and at 2.83 ± 0.07 ns, respectively, both of which match previous reports and multi-frequency analyses. This paper suggests the CRPO as a new method to extract the FLT in problematic cases such as high MCP gains and heterogeneous environments. In traditional FD FLIM measurements, the variation in phase angle and modulation are measured. By measuring over varying DC currents, another variation is detected in the FLT determined through the phase and modulation methods, with the CRPO indicating the true FLT.
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Affiliation(s)
- Gilad Yahav
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Eran Barnoy
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Nir Roth
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, 5290002, Ramat Gan, Israel
| | - Lior Turgeman
- Joseph M. Katz Graduate School of Business, University of Pittsburgh, Roberto Clemente Dr, PA, 15260, Pittsburgh, USA
| | - Dror Fixler
- Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, 5290002, Ramat Gan, Israel
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13
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Le Marois A, Labouesse S, Suhling K, Heintzmann R. Noise-Corrected Principal Component Analysis of fluorescence lifetime imaging data. JOURNAL OF BIOPHOTONICS 2017; 10:1124-1133. [PMID: 27943625 DOI: 10.1002/jbio.201600160] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/23/2016] [Accepted: 11/14/2016] [Indexed: 05/08/2023]
Abstract
Fluorescence Lifetime Imaging (FLIM) is an attractive microscopy method in the life sciences, yielding information on the sample otherwise unavailable through intensity-based techniques. A novel Noise-Corrected Principal Component Analysis (NC-PCA) method for time-domain FLIM data is presented here. The presence and distribution of distinct microenvironments are identified at lower photon counts than previously reported, without requiring prior knowledge of their number or of the dye's decay kinetics. A noise correction based on the Poisson statistics inherent to Time-Correlated Single Photon Counting is incorporated. The approach is validated using simulated data, and further applied to experimental FLIM data of HeLa cells stained with membrane dye di-4-ANEPPDHQ. Two distinct lipid phases were resolved in the cell membranes, and the modification of the order parameters of the plasma membrane during cholesterol depletion was also detected. Noise-corrected Principal Component Analysis of FLIM data resolves distinct microenvironments in cell membranes of live HeLa cells.
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Affiliation(s)
- Alix Le Marois
- Department of Physics, King's College London, Strand, WC2R 2LS, London, United Kingdom
| | - Simon Labouesse
- Institute Fresnel, Avenue Escadrille Normandie Niemen, 13013, Marseille, France
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, WC2R 2LS, London, United Kingdom
| | - Rainer Heintzmann
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Abbe Centre of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
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14
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Hirvonen LM, Fisher-Levine M, Suhling K, Nomerotski A. Photon counting phosphorescence lifetime imaging with TimepixCam. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:013104. [PMID: 28147700 DOI: 10.1063/1.4973717] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
TimepixCam is a novel fast optical imager based on an optimized silicon pixel sensor with a thin entrance window and read out by a Timepix Application Specific Integrated Circuit. The 256 × 256 pixel sensor has a time resolution of 15 ns at a sustained frame rate of 10 Hz. We used this sensor in combination with an image intensifier for wide-field time-correlated single photon counting imaging. We have characterised the photon detection capabilities of this detector system and employed it on a wide-field epifluorescence microscope to map phosphorescence decays of various iridium complexes with lifetimes of about 1 μs in 200 μm diameter polystyrene beads.
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Affiliation(s)
- Liisa M Hirvonen
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | | | - Klaus Suhling
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
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15
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Sparks H, Görlitz F, Kelly DJ, Warren SC, Kellett PA, Garcia E, Dymoke-Bradshaw AKL, Hares JD, Neil MAA, Dunsby C, French PMW. Characterisation of new gated optical image intensifiers for fluorescence lifetime imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:013707. [PMID: 28147687 DOI: 10.1063/1.4973917] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report the characterisation of gated optical image intensifiers for fluorescence lifetime imaging, evaluating the performance of several different prototypes that culminate in a new design that provides improved spatial resolution conferred by the addition of a magnetic field to reduce the lateral spread of photoelectrons on their path between the photocathode and microchannel plate, and higher signal to noise ratio conferred by longer time gates. We also present a methodology to compare these systems and their capabilities, including the quantitative readouts of Förster resonant energy transfer.
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Affiliation(s)
- H Sparks
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - F Görlitz
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - D J Kelly
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - S C Warren
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - P A Kellett
- Kentech Instruments Ltd., Howbery Park, Wallingford OX10 8BD, United Kingdom
| | - E Garcia
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | | | - J D Hares
- Kentech Instruments Ltd., Howbery Park, Wallingford OX10 8BD, United Kingdom
| | - M A A Neil
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - C Dunsby
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
| | - P M W French
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BW, United Kingdom
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16
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Zhang Y, Khan AA, Vigil GD, Howard SS. Investigation of signal-to-noise ratio in frequency-domain multiphoton fluorescence lifetime imaging microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2016; 33:B1-B11. [PMID: 27409702 DOI: 10.1364/josaa.33.0000b1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Multiphoton microscopy (MPM) combined with fluorescence lifetime imaging microscopy (FLIM) has enabled three-dimensional quantitative molecular microscopy in vivo. The signal-to-noise ratio (SNR), and thus the imaging rate of MPM-FLIM, which is fundamentally limited by the shot noise and fluorescence saturation, has not been quantitatively studied yet. In this paper, we investigate the SNR performance of the frequency-domain (FD) MPM-FLIM with two figures of merit: the photon economy in the limit of shot noise, and the normalized SNR in the limit of saturation. The theoretical results and Monte Carlo simulations find that two-photon FD-FLIM requires 50% fewer photons to achieve the same SNR as conventional one-photon FLIM. We also analytically show that the MPM-FD-FLIM can exploit the DC and higher harmonic components generated by nonlinear optical mixing of the excitation light to improve SNR, reducing the required number of photons by an additional 50%. Finally, the effect of fluorophore saturation on the experimental SNR performance is discussed.
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17
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Poland SP, Erdogan AT, Krstajić N, Levitt J, Devauges V, Walker RJ, Li DDU, Ameer-Beg SM, Henderson RK. New high-speed centre of mass method incorporating background subtraction for accurate determination of fluorescence lifetime. OPTICS EXPRESS 2016; 24:6899-915. [PMID: 27136986 DOI: 10.1364/oe.24.006899] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We demonstrate an implementation of a centre-of-mass method (CMM) incorporating background subtraction for use in multifocal fluorescence lifetime imaging microscopy to accurately determine fluorescence lifetime in live cell imaging using the Megaframe camera. The inclusion of background subtraction solves one of the major issues associated with centre-of-mass approaches, namely the sensitivity of the algorithm to background signal. The algorithm, which is predominantly implemented in hardware, provides real-time lifetime output and allows the user to effectively condense large amounts of photon data. Instead of requiring the transfer of thousands of photon arrival times, the lifetime is simply represented by one value which allows the system to collect data up to limit of pulse pile-up without any limitations on data transfer rates. In order to evaluate the performance of this new CMM algorithm with existing techniques (i.e. rapid lifetime determination and Levenburg-Marquardt), we imaged live MCF-7 human breast carcinoma cells transiently transfected with FRET standards. We show that, it offers significant advantages in terms of lifetime accuracy and insensitivity to variability in dark count rate (DCR) between Megaframe camera pixels. Unlike other algorithms no prior knowledge of the expected lifetime is required to perform lifetime determination. The ability of this technique to provide real-time lifetime readout makes it extremely useful for a number of applications.
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18
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Tsikouras A, Berman R, Andrews DW, Fang Q. High-speed multifocal array scanning using refractive window tilting. BIOMEDICAL OPTICS EXPRESS 2015; 6:3737-47. [PMID: 26504625 PMCID: PMC4605034 DOI: 10.1364/boe.6.003737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 08/20/2015] [Accepted: 08/22/2015] [Indexed: 05/10/2023]
Abstract
Confocal microscopy has several advantages over wide-field microscopy, such as out-of-focus light suppression, 3D sectioning, and compatibility with specialized detectors. While wide-field microscopy is a faster approach, multiplexed confocal schemes can be used to make confocal microscopy more suitable for high-throughput applications, such as high-content screening (HCS) commonly used in drug discovery. An increasingly powerful modality in HCS is fluorescence lifetime imaging microscopy (FLIM), which can be used to measure protein-protein interactions through Förster resonant energy transfer (FRET). FLIM-FRET for HCS combines the requirements of high throughput, high resolution and specialized time-resolving detectors, making it difficult to implement using wide-field and spinning disk confocal approaches. We developed a novel foci array scan method that can achieve uniform multiplex confocal acquisition using stationary lenslet arrays for high resolution and high throughput FLIM. Unlike traditional mirror galvanometers, which work in Fourier space between scan lenses, this scan method uses optical flats to steer a 2-dimension foci array through refraction. After integrating this scanning scheme in a multiplexing confocal FLIM system, we demonstrate it offers clear benefits over traditional mirror galvanometer scanners in scan linearity, uniformity, cost and complexity.
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Affiliation(s)
- Anthony Tsikouras
- Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Richard Berman
- Spectral Applied Research, 2 East Beaver Creek Rd., Bldg. #2, Richmond Hill, Ontario, L4B 2N3, Canada
| | - David W. Andrews
- Department of Biochemistry, Sunnybrook Research Institute, University of Toronto, 2075 Bayview Ave., Toronto, Ontario, M4N 3M5, Canada
| | - Qiyin Fang
- Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
- Department of Biomedical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
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19
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De Los Santos C, Chang CW, Mycek MA, Cardullo RA. FRAP, FLIM, and FRET: Detection and analysis of cellular dynamics on a molecular scale using fluorescence microscopy. Mol Reprod Dev 2015; 82:587-604. [PMID: 26010322 PMCID: PMC4515154 DOI: 10.1002/mrd.22501] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/01/2015] [Indexed: 01/01/2023]
Abstract
The combination of fluorescent-probe technology plus modern optical microscopes allows investigators to monitor dynamic events in living cells with exquisite temporal and spatial resolution. Fluorescence recovery after photobleaching (FRAP), for example, has long been used to monitor molecular dynamics both within cells and on cellular surfaces. Although bound by the diffraction limit imposed on all optical microscopes, the combination of digital cameras and the application of fluorescence intensity information on large-pixel arrays have allowed such dynamic information to be monitored and quantified. Fluorescence lifetime imaging microscopy (FLIM), on the other hand, utilizes the information from an ensemble of fluorophores to probe changes in the local environment. Using either fluorescence-intensity or lifetime approaches, fluorescence resonance energy transfer (FRET) microscopy provides information about molecular interactions, with Ångstrom resolution. In this review, we summarize the theoretical framework underlying these methods and illustrate their utility in addressing important problems in reproductive and developmental systems.
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Affiliation(s)
- Carla De Los Santos
- Departments of Biology and Bioengineering, University of California, Riverside, Riverside, CA 92501
| | - Ching-Wei Chang
- Department of Bioengineering, University of California, Berkeley 94720
| | - Mary-Ann Mycek
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Richard A. Cardullo
- Departments of Biology and Bioengineering, University of California, Riverside, Riverside, CA 92501
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20
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21
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Dean KM, Davis LM, Lubbeck JL, Manna P, Friis P, Palmer AE, Jimenez R. High-speed multiparameter photophysical analyses of fluorophore libraries. Anal Chem 2015; 87:5026-30. [PMID: 25898152 DOI: 10.1021/acs.analchem.5b00607] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There is a critical need for high-speed multiparameter photophysical measurements of large libraries of fluorescent probe variants for imaging and biosensor development. We present a microfluidic flow cytometer that rapidly assays 10(4)-10(5) member cell-based fluorophore libraries, simultaneously measuring fluorescence lifetime and photobleaching. Together, these photophysical characteristics determine imaging performance. We demonstrate the ability to resolve the diverse photophysical characteristics of different library types and the ability to identify rare populations.
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Affiliation(s)
- Kevin M Dean
- †BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, United States.,‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Lloyd M Davis
- §Department of Physics, University of Tennessee Knoxville, Knoxville, Tennessee 37996, United States.,∥Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388, United States
| | - Jennifer L Lubbeck
- ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States.,⊥JILA, NIST, and University of Colorado, Boulder, Colorado 80309, United States
| | - Premashis Manna
- ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States.,⊥JILA, NIST, and University of Colorado, Boulder, Colorado 80309, United States
| | - Pia Friis
- ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States.,⊥JILA, NIST, and University of Colorado, Boulder, Colorado 80309, United States
| | - Amy E Palmer
- †BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, United States.,‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Ralph Jimenez
- ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States.,⊥JILA, NIST, and University of Colorado, Boulder, Colorado 80309, United States
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22
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Poland SP, Krstajić N, Monypenny J, Coelho S, Tyndall D, Walker RJ, Devauges V, Richardson J, Dutton N, Barber P, Li DDU, Suhling K, Ng T, Henderson RK, Ameer-Beg SM. A high speed multifocal multiphoton fluorescence lifetime imaging microscope for live-cell FRET imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6:277-96. [PMID: 25780724 PMCID: PMC4354599 DOI: 10.1364/boe.6.000277] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/28/2014] [Accepted: 11/30/2014] [Indexed: 05/18/2023]
Abstract
We demonstrate diffraction limited multiphoton imaging in a massively parallel, fully addressable time-resolved multi-beam multiphoton microscope capable of producing fluorescence lifetime images with sub-50ps temporal resolution. This imaging platform offers a significant improvement in acquisition speed over single-beam laser scanning FLIM by a factor of 64 without compromising in either the temporal or spatial resolutions of the system. We demonstrate FLIM acquisition at 500 ms with live cells expressing green fluorescent protein. The applicability of the technique to imaging protein-protein interactions in live cells is exemplified by observation of time-dependent FRET between the epidermal growth factor receptor (EGFR) and the adapter protein Grb2 following stimulation with the receptor ligand. Furthermore, ligand-dependent association of HER2-HER3 receptor tyrosine kinases was observed on a similar timescale and involved the internalisation and accumulation or receptor heterodimers within endosomes. These data demonstrate the broad applicability of this novel FLIM technique to the spatio-temporal dynamics of protein-protein interaction.
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Affiliation(s)
- Simon P. Poland
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
| | - Nikola Krstajić
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
| | - James Monypenny
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
| | - Simao Coelho
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
| | - David Tyndall
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
| | - Richard J. Walker
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
- Photon-Force Ltd., Edinburgh,
UK
| | - Viviane Devauges
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
| | - Justin Richardson
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
- Photon-Force Ltd., Edinburgh,
UK
| | - Neale Dutton
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
| | - Paul Barber
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ
UK
| | - David Day-Uei Li
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161 Cathedral Street, Glasgow, G4 0RE,
UK
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, London,
UK
| | - Tony Ng
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
- UCL Cancer Institute, Paul O'Gorman Building, University College London, London WC1E 6DD,
UK
| | - Robert K. Henderson
- Institute for Integrated Micro and Nano Systems, School of Engineering, University of Edinburgh, Edinburgh,
UK
| | - Simon M. Ameer-Beg
- Division of Cancer Studies, Guy’s Campus, Kings College, London,
UK
- Randall Division of Cell and Molecular Biophysics, Guy’s Campus, Kings College, London,
UK
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23
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Hirvonen LM, Jiggins S, Sergent N, Zanda G, Suhling K. Photon counting imaging with an electron-bombarded CCD: towards a parallel-processing photoelectronic time-to-amplitude converter. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:123102. [PMID: 25554267 DOI: 10.1063/1.4901935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have used an electron-bombarded CCD for optical photon counting imaging. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. We propose on this basis that a gain voltage sweep during exposure in an electron-bombarded sensor would allow photon arrival time determination with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter, or a two-dimensional photon counting streak camera. Several applications that require timing of photon arrival, including Fluorescence Lifetime Imaging Microscopy, may benefit from such an approach. A simulation of a voltage sweep performed with experimental data collected with different acceleration voltages validates the principle of this approach. Moreover, photon event centroiding was performed and a hybrid 50% Gaussian/Centre of Gravity + 50% Hyperbolic cosine centroiding algorithm was found to yield the lowest fixed pattern noise. Finally, the camera was mounted on a fluorescence microscope to image F-actin filaments stained with the fluorescent dye Alexa 488 in fixed cells.
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Affiliation(s)
- Liisa M Hirvonen
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - Stephen Jiggins
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - Nicolas Sergent
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - Gianmarco Zanda
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - Klaus Suhling
- Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom
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24
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Hirvonen LM, Festy F, Suhling K. Wide-field time-correlated single-photon counting (TCSPC) lifetime microscopy with microsecond time resolution. OPTICS LETTERS 2014; 39:5602-5. [PMID: 25360938 DOI: 10.1364/ol.39.005602] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A 1 MHz frame rate complementary metal-oxide semiconductor (CMOS) camera was used in combination with an image intensifier for wide-field time-correlated single-photon counting (TCSPC) imaging. The system combines an ultrafast frame rate with single-photon sensitivity and was employed on a fluorescence microscope to image decays of ruthenium compound Ru(dpp) with lifetimes from around 1 to 5 μs. A submicrowatt excitation power over the whole field of view is sufficient for this approach, and compatibility with live-cell imaging was demonstrated by imaging europium-containing beads with a lifetime of 570 μs in living HeLa cells. A standard two-photon excitation scanning fluorescence lifetime imaging (FLIM) system was used to independently verify the lifetime for the europium beads. This approach brings together advantageous features for time-resolved live-cell imaging such as low excitation intensity, single-photon sensitivity, ultrafast camera frame rates, and short acquisition times.
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25
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Turgeman L, Fixler D. The influence of dead time related distortions on live cell fluorescence lifetime imaging (FLIM) experiments. JOURNAL OF BIOPHOTONICS 2014; 7:442-452. [PMID: 23674214 DOI: 10.1002/jbio.201300018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/10/2013] [Accepted: 04/23/2013] [Indexed: 06/02/2023]
Abstract
Recent developments in the field of fluorescence lifetime imaging microscopy (FLIM) techniques allow the use of high repetition rate light sources in live cell experiments. For light sources with a repetition rate of 20-100 MHz, the time-correlated single photon counting (TCSPC) FLIM systems suffer serious dead time related distortions, known as "inter-pulse pile-up". The objective of this paper is to present a new method to quantify the level of signal distortion in TCSPC FLIM experiments, in order to determine the most efficient laser repetition rate for different FLT ranges. Optimization of the F -value, which is the relation between the relative standard deviation (RSD) in the measured FLT to the RSD in the measured fluorescence intensity (FI), allows quantification of the level of FI signal distortion, as well as determination of the correct FLT of the measurement. It is shown that by using a very high repetition rate (80 MHz) for samples characterized by high real FLT's (4-5 ns), virtual short FLT components are added to the FLT histogram while a F -value that is higher than 1 is obtained. For samples characterized with short real FLT's, virtual long FLT components are added to the FLT histogram with the lower repetition rate (20-50 MHz), while by using a higher repetition rate (80 MHz) the "inter-pulse pile-up" is eliminated as the F -value is close to 1.
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Affiliation(s)
- Lior Turgeman
- Faculty of Engineering and Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan, 52900, Israel
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26
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Abstract
Fluorescence can be characterized by its intensity, position, wavelength, lifetime, and polarization. The more of these features are acquired in a single measurement, the more can be learned about the sample, i.e., the microenvironment of the fluorescence probe. Polarization-resolved fluorescence lifetime imaging-time-resolved fluorescence anisotropy imaging, TR-FAIM-allows mapping of viscosity or binding or of homo-FRET which can indicate dimerization or generally oligomerization.
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Affiliation(s)
- Klaus Suhling
- Department of Physics, King's College London, London, UK
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27
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Esposito A, Popleteeva M, Venkitaraman AR. Maximizing the biochemical resolving power of fluorescence microscopy. PLoS One 2013; 8:e77392. [PMID: 24204821 PMCID: PMC3810478 DOI: 10.1371/journal.pone.0077392] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 09/02/2013] [Indexed: 11/19/2022] Open
Abstract
Most recent advances in fluorescence microscopy have focused on achieving spatial resolutions below the diffraction limit. However, the inherent capability of fluorescence microscopy to non-invasively resolve different biochemical or physical environments in biological samples has not yet been formally described, because an adequate and general theoretical framework is lacking. Here, we develop a mathematical characterization of the biochemical resolution in fluorescence detection with Fisher information analysis. To improve the precision and the resolution of quantitative imaging methods, we demonstrate strategies for the optimization of fluorescence lifetime, fluorescence anisotropy and hyperspectral detection, as well as different multi-dimensional techniques. We describe optimized imaging protocols, provide optimization algorithms and describe precision and resolving power in biochemical imaging thanks to the analysis of the general properties of Fisher information in fluorescence detection. These strategies enable the optimal use of the information content available within the limited photon-budget typically available in fluorescence microscopy. This theoretical foundation leads to a generalized strategy for the optimization of multi-dimensional optical detection, and demonstrates how the parallel detection of all properties of fluorescence can maximize the biochemical resolving power of fluorescence microscopy, an approach we term Hyper Dimensional Imaging Microscopy (HDIM). Our work provides a theoretical framework for the description of the biochemical resolution in fluorescence microscopy, irrespective of spatial resolution, and for the development of a new class of microscopes that exploit multi-parametric detection systems.
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Affiliation(s)
- Alessandro Esposito
- Medical Research Council Cancer Unit, University of Cambridge, Cambridge, United Kingdom
| | - Marina Popleteeva
- Medical Research Council Cancer Unit, University of Cambridge, Cambridge, United Kingdom
| | - Ashok R. Venkitaraman
- Medical Research Council Cancer Unit, University of Cambridge, Cambridge, United Kingdom
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28
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Turgeman L, Fixler D. Photon Efficiency Optimization in Time-Correlated Single Photon Counting Technique for Fluorescence Lifetime Imaging Systems. IEEE Trans Biomed Eng 2013; 60:1571-9. [DOI: 10.1109/tbme.2013.2238671] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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29
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30
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Kang D, Kupinski MA. Effect of noise on modulation amplitude and phase in frequency-domain diffusive imaging. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:016010. [PMID: 22352660 PMCID: PMC4098065 DOI: 10.1117/1.jbo.17.1.016010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 11/13/2011] [Accepted: 11/16/2011] [Indexed: 05/30/2023]
Abstract
We theoretically investigate the effect of noise on frequency-domain heterodyne and/or homodyne measurements of intensity-modulated beams propagating through diffusive media, such as a photon density wave. We assumed that the attenuated amplitude and delayed phase are estimated by taking the Fourier transform of the noisy, modulated output data. We show that the estimated amplitude and phase are biased when the number of output photons is small. We also show that the use of image intensifiers for photon amplification in heterodyne or homodyne measurements increases the amount of biases. Especially, it turns out that the biased estimation is independent of AC-dependent noise in sinusoidal heterodyne or homodyne outputs. Finally, the developed theory indicates that the previously known variance model of modulation amplitude and phase is not valid in low light situations. Monte-Carlo simulations with varied numbers of input photons verify our theoretical trends of the bias.
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Affiliation(s)
- Dongyel Kang
- University of Arizona, College of Optical Sciences, 1630 East University Boulevard, Tucson, Arizona 85721, USA.
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31
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Kang D, Kupinski MA. Noise characteristics of heterodyne/homodyne frequency-domain measurements. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:015002. [PMID: 22352646 PMCID: PMC3603149 DOI: 10.1117/1.jbo.17.1.015002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 10/27/2011] [Accepted: 11/04/2011] [Indexed: 05/22/2023]
Abstract
We theoretically develop and experimentally validate the noise characteristics of heterodyne and/or homodyne measurements that are widely used in frequency-domain diffusive imaging. The mean and covariance of the modulated heterodyne output are derived by adapting the random amplification of a temporal point process. A multinomial selection rule is applied to the result of the temporal noise analysis to additionally model the spatial distribution of intensified photons measured by a charge-coupled device (CCD), which shows that the photon detection efficiency of CCD pixels plays an important role in the noise property of detected photons. The approach of using a multinomial probability law is validated from experimental results. Also, experimentally measured characteristics of means and variances of homodyne outputs are in agreement with the developed theory. The developed noise model can be applied to all photon amplification processes.
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Affiliation(s)
- Dongyel Kang
- University of Arizona, College of Optical Sciences, 1630 E. University Boulevard, Tucson, Arizona 85721, USA.
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32
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Won YJ, Han WT, Kim DY. Precision and accuracy of the analog mean-delay method for high-speed fluorescence lifetime measurement. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2011; 28:2026-32. [PMID: 21979507 DOI: 10.1364/josaa.28.002026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The analog mean-delay (AMD) method is a new alternative method to measure the lifetime of a fluorescence molecule. Because of its powerful advantages of accurate lifetime determination, good photon economy, and a high photon detection rate, the AMD method is considered to be very suitable for high-speed confocal fluorescence lifetime imaging microscopy (FLIM). For the practical usage of the AMD method in FLIM (AMD-FLIM), detailed study on various experimental conditions and parameters that affect the precision and the accuracy of the AMD method is required. In this paper, we present the relation between the precision and accuracy of the lifetime versus iteration number in the AMD method, the best cutoff frequency of a low-pass filter used in the AMD-FLIM system for a given fluorophore, and the optimum position and width of the integration window by using Monte Carlo simulations and a series of AMD-FLIM experiments.
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Affiliation(s)
- Young Jae Won
- Department of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, Korea
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33
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Zhao Q, Young IT, de Jong JGS. Photon budget analysis for fluorescence lifetime imaging microscopy. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:086007. [PMID: 21895319 DOI: 10.1117/1.3608997] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have constructed a mathematical model to analyze the photon efficiency of frequency-domain fluorescence lifetime imaging microscopy (FLIM). The power of the light source needed for illumination in a FLIM system and the signal-to-noise ratio of the detector have led us to a photon "budget." These measures are relevant to many fluorescence microscope users and the results are not restricted to FLIM but applicable to widefield fluorescence microscopy in general. Limitations in photon numbers, however, are more of an issue with FLIM compared to other less quantitative types of imaging. By modeling a typical experimental configuration, examples are given for fluorophores whose absorption peaks span the visible spectrum from Fura-2 to Cy5. We have performed experiments to validate the assumptions and parameters used in our mathematical model. The influence of fluorophore concentration on the intensity of the fluorescence emission light and the Poisson distribution assumption of the detected fluorescence emission light have been validated. The experimental results agree well with the mathematical model. This photon budget is important in order to characterize the constraints involved in current fluorescent microscope systems that are used for lifetime as well as intensity measurements and to design and fabricate new systems.
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Affiliation(s)
- Qiaole Zhao
- Delft University of Technology, Department of Imaging Science and Technology, The Netherlands
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34
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Fruhwirth GO, Fernandes LP, Weitsman G, Patel G, Kelleher M, Lawler K, Brock A, Poland SP, Matthews DR, Kéri G, Barber PR, Vojnovic B, Ameer‐Beg SM, Coolen ACC, Fraternali F, Ng T. How Förster Resonance Energy Transfer Imaging Improves the Understanding of Protein Interaction Networks in Cancer Biology. Chemphyschem 2011; 12:442-61. [DOI: 10.1002/cphc.201000866] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/07/2011] [Indexed: 01/22/2023]
Affiliation(s)
- Gilbert O. Fruhwirth
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Luis P. Fernandes
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Gregory Weitsman
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Gargi Patel
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Muireann Kelleher
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Katherine Lawler
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Adrian Brock
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - Simon P. Poland
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Daniel R. Matthews
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
| | - György Kéri
- Vichem Chemie Research Ltd. Herman Ottó utca 15, Budapest, Hungary and Pathobiochemistry Research Group of Hungarian Academy of Science, Semmelweis University, Budapest, 1444 Bp 8. POB 260 (Hungary)
| | - Paul R. Barber
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ (UK)
| | - Borivoj Vojnovic
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Gray Institute for Radiation Oncology & Biology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ (UK)
| | - Simon M. Ameer‐Beg
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Anthony C. C. Coolen
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Department of Mathematics, King's College London, Strand Campus, London, WC2R 2LS (UK)
| | - Franca Fraternali
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
| | - Tony Ng
- Richard Dimbleby Department of Cancer Research, Division of Cancer Studies, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK), Fax: (+44) (0) 20 7848 6220, Fax: (+44) (0) 20 7848 8056
- Randall Division of Cell & Molecular Biophysics, King's College London, Guy's Medical School Campus, NHH, SE1 1UL (UK)
- Comprehensive Cancer Imaging Centre, New Hunt's House, Guy's Medical School Campus, NHH, SE1 1UL (UK)
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35
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Won Y, Moon S, Yang W, Kim D, Han WT, Kim DY. High-speed confocal fluorescence lifetime imaging microscopy (FLIM) with the analog mean delay (AMD) method. OPTICS EXPRESS 2011; 19:3396-405. [PMID: 21369162 DOI: 10.1364/oe.19.003396] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We demonstrate a high-speed confocal fluorescence lifetime imaging microscopy (FLIM) whose accuracy and photon economy are as good as that of a time-correlated single photon counting (TCSPC). It is based on a new lifetime determination scheme, the analog mean delay (AMD) method. Due to the technical advantages of multiple fluorescence photon detection capability, accurate lifetime determination scheme and high photon detection efficiency, the AMD method can be the most effective method for high-speed confocal FLIM. The feasibility of real-time confocal FLIM with the AMD method has been demonstrated by observing the dynamic reaction of calcium channels in a RBL-2H3 cell with respect to 4αPDD stimulus. We have achieved the photon detection rate of 125 times faster than a conventional TCSPC based system in this experiment.
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Affiliation(s)
- Youngjae Won
- Department of Information and Communications, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea
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36
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Giraud G, Schulze H, Li DU, Bachmann TT, Crain J, Tyndall D, Richardson J, Walker R, Stoppa D, Charbon E, Henderson R, Arlt J. Fluorescence lifetime biosensing with DNA microarrays and a CMOS-SPAD imager. BIOMEDICAL OPTICS EXPRESS 2010; 1:1302-1308. [PMID: 21258550 PMCID: PMC3018131 DOI: 10.1364/boe.1.001302] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/12/2010] [Accepted: 10/30/2010] [Indexed: 05/07/2023]
Abstract
Fluorescence lifetime of dye molecules is a sensitive reporter on local microenvironment which is generally independent of fluorophores concentration and can be used as a means of discrimination between molecules with spectrally overlapping emission. It is therefore a potentially powerful multiplexed detection modality in biosensing but requires extremely low light level operation typical of biological analyte concentrations, long data acquisition periods and on-chip processing capability to realize these advantages. We report here fluorescence lifetime data obtained using a CMOS-SPAD imager in conjunction with DNA microarrays and TIRF excitation geometry. This enables acquisition of single photon arrival time histograms for a 320 pixel FLIM map within less than 26 seconds exposure time. From this, we resolve distinct lifetime signatures corresponding to dye-labelled HCV and quantum-dot-labelled HCMV nucleic acid targets at concentrations as low as 10 nM.
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Affiliation(s)
- Gerard Giraud
- COSMIC & School of Physics and Astronomy,
SUPA, The University of Edinburgh, The King’s
Buildings,
EH9 3JZ Edinburgh, UK
| | - Holger Schulze
- Division of Pathway Medicine, College of Medicine and
Veterinary Medicine, The University of Edinburgh, Chancellor’s
Building, Little France Crescent, EH16 4SB Edinburgh, UK
| | - Day-Uei Li
- The Institute for Integrated Micro and Nano Systems,
School of Engineering and Electronics, The University
of Edinburgh,
The King’s Buildings, EH9 3JL Edinburgh, UK
| | - Till T. Bachmann
- Division of Pathway Medicine, College of Medicine and
Veterinary Medicine, The University of Edinburgh, Chancellor’s
Building, Little France Crescent, EH16 4SB Edinburgh, UK
| | - Jason Crain
- COSMIC & School of Physics and Astronomy,
SUPA, The University of Edinburgh, The King’s
Buildings,
EH9 3JZ Edinburgh, UK
- National Physical Laboratory, Hampton Road,
Teddington, Middlesex TW11 0LW, UK
| | - David Tyndall
- The Institute for Integrated Micro and Nano Systems,
School of Engineering and Electronics, The University
of Edinburgh,
The King’s Buildings, EH9 3JL Edinburgh, UK
| | - Justin Richardson
- Imaging Division, ST Microelectronics, Edinburgh EH12
7BF, UK
- Currently at Selex Galileo, A Finmeccanica Company, 2
Crewe Road North, Edinburgh, EH5 2XS, UK
| | - Richard Walker
- The Institute for Integrated Micro and Nano Systems,
School of Engineering and Electronics, The University
of Edinburgh,
The King’s Buildings, EH9 3JL Edinburgh, UK
| | - David Stoppa
- Smart Optical Sensors and Interfaces, Fondazione
Bruno Kessler, Trento, Italy
| | - Edoardo Charbon
- EEMCS Faculty, Delft University of Technology,
Mekelweg 4, 2628CD Delft, Netherlands
| | - Robert Henderson
- The Institute for Integrated Micro and Nano Systems,
School of Engineering and Electronics, The University
of Edinburgh,
The King’s Buildings, EH9 3JL Edinburgh, UK
| | - Jochen Arlt
- COSMIC & School of Physics and Astronomy,
SUPA, The University of Edinburgh, The King’s
Buildings,
EH9 3JZ Edinburgh, UK
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37
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Wessels JT, Yamauchi K, Hoffman RM, Wouters FS. Advances in cellular, subcellular, and nanoscale imaging in vitro and in vivo. Cytometry A 2010; 77:667-76. [PMID: 20564541 DOI: 10.1002/cyto.a.20931] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This review focuses on technical advances in fluorescence microscopy techniques including laser scanning techniques, fluorescence-resonance energy transfer (FRET) microscopy, fluorescence lifetime imaging (FLIM), stimulated emission depletion (STED)-based super-resolution microscopy, scanning confocal endomicroscopes, thin-sheet laser imaging microscopy (TSLIM), and tomographic techniques such as early photon tomography (EPT) as well as on clinical laser-based endoscopic and microscopic techniques. We will also discuss the new developments in the field of fluorescent dyes and fluorescent genetic reporters that enable new possibilities in high-resolution and molecular imaging both in in vitro and in vivo. Small animal and tissue imaging benefit from the development of new fluorescent proteins, dyes, and sensing constructs that operate in the far red and near-infrared spectrum.
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Affiliation(s)
- Johannes T Wessels
- Department of Nephrology and Rheumatology, Molecular and Optical Live Cell Imaging, Center for Internal Medicine, University Medicine Goettingen, Göttingen, Germany.
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38
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Chang CW, Mycek MA. Enhancing precision in time-domain fluorescence lifetime imaging. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:056013. [PMID: 21054107 PMCID: PMC2966491 DOI: 10.1117/1.3494566] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In biological applications of fluorescence lifetime imaging, low signals from samples can be a challenge, causing poor lifetime precision. We demonstrate how optimal signal gating (a method applied to the temporal dimension of a lifetime image) and novel total variation denoising models (a method applied to the spatial dimension of a lifetime image) can be used in time-domain fluorescence lifetime imaging microscopy (FLIM) to improve lifetime precision. In time-gated FLIM, notable fourfold precision improvements were observed in a low-light example. This approach can be employed to improve FLIM data while minimizing sample light exposure and increasing imaging speed.
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Affiliation(s)
- Ching-Wei Chang
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan 48109-2099, USA
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39
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Estrada AD, Dunn AK. Improved sensitivity for two-photon frequency-domain lifetime measurement. OPTICS EXPRESS 2010; 18:13631-13639. [PMID: 20588496 DOI: 10.1364/oe.18.013631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate a method to improve the measurement sensitivity of two-photon frequency-domain lifetime measurements in poor signal to background conditions. This technique uses sinusoidal modulation of the two-photon excitation source and detection of the second harmonic of the modulation frequency that appears in the emission. Additionally, we present the mathematical model which describes how the observed phase shift and amplitude demodulation factor of two-photon phosphorescence emission are related to the phosphorescence lifetime and modulation frequency. We demonstrate the validity of the model by showing the existence of new frequency terms in the phosphorescence emission generated from the quadratic nature of two-photon absorption and by showing that the phase shift and demodulation match theory for all frequency components.
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Affiliation(s)
- Arnold D Estrada
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, C0800, Austin, TX 78712, USA.
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40
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Lin Y, Gmitro AF. Statistical analysis and optimization of frequency-domain fluorescence lifetime imaging microscopy using homodyne lock-in detection. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2010; 27:1145-1155. [PMID: 20448782 DOI: 10.1364/josaa.27.001145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Fluorescence lifetime imaging microscopy is used widely in biological research, but the accuracy and precision of lifetime measurements are limited. Photon noise is an inherent error source that cannot be eliminated. In this paper, we present a general approach to compute the probability density of the estimated lifetime for frequency-domain fluorescence lifetime imaging microscopy using homodyne lock-in detection. The analysis for commonly used excitation methods, including sinusoidal modulation, square-wave modulation, and a periodically pulsed light source, are given and compared to the results of Monte Carlo simulations. The optimum parameters of the excitation waveforms to minimize the variance of the estimated lifetimes are also derived and compared to previously published results.
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Affiliation(s)
- Yuxiang Lin
- College of Optical Sciences, University of Arizona, 1630 East University Boulevard, Tucson, Arizona 85721, USA
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41
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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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42
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Schlachter S, Elder AD, Esposito A, Kaminski GS, Frank JH, van Geest LK, Kaminski CF. mhFLIM: resolution of heterogeneous fluorescence decays in widefield lifetime microscopy. OPTICS EXPRESS 2009; 17:1557-70. [PMID: 19188985 DOI: 10.1364/oe.17.001557] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Frequency-domain fluorescence lifetime imaging microscopy (FD-FLIM) is a fast and accurate way of measuring fluorescence lifetimes in widefield microscopy. However, the resolution of multiple exponential fluorescence decays has remained beyond the reach of most practical FD-FLIM systems. In this paper we describe the implementation of FD-FLIM using a 40 MHz pulse train derived from a supercontinuum source for excitation. The technique, which we term multi-harmonic FLIM (mhFLIM), makes it possible to accurately resolve biexponential decays of fluorophores without any a priori information. The system's performance is demonstrated using a mixture of spectrally similar dyes of known composition and also on a multiply-labeled biological sample. The results are compared to those obtained from time correlated single photon counting (TCSPC) microscopy and a good level of agreement is achieved. We also demonstrate the first practical application of an algorithm derived by G. Weber [1] for analysing mhFLIM data. Because it does not require nonlinear minimisation, it offers potential for realtime analysis during acquisition.
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Affiliation(s)
- S Schlachter
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
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43
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Levitt JA, Matthews DR, Ameer-Beg SM, Suhling K. Fluorescence lifetime and polarization-resolved imaging in cell biology. Curr Opin Biotechnol 2009; 20:28-36. [DOI: 10.1016/j.copbio.2009.01.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 01/23/2009] [Indexed: 10/21/2022]
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44
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Chapter 3 Time domain FLIM: Theory, instrumentation, and data analysis. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s0075-7535(08)00003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
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45
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Wessels JT, Hoffman RM, Wouters FS. The use of transgenic fluorescent mouse strains, fluorescent protein coding vectors, and innovative imaging techniques in the life sciences. Cytometry A 2008; 73:490-1. [PMID: 18307256 DOI: 10.1002/cyto.a.20548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Johannes T Wessels
- Department of Nephrology/ Rheumatology, Centre of Internal Medicine, Molecular and Optical Live Cell Imaging (MOLCI), University of Medicine, Goettingen, Germany.
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46
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Wouters FS, Esposito A. Quantitative analysis of fluorescence lifetime imaging made easy. HFSP JOURNAL 2008; 2:7-11. [PMID: 19404448 PMCID: PMC2640995 DOI: 10.2976/1.2833600] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Indexed: 11/19/2022]
Abstract
Fluorescence lifetime imaging is a valuable and versatile tool for the investigation of the molecular environment of fluorophores in living cells. It is ideally suited-and is therefore increasingly used-for the quantification of the occurrence of Förster Resonance Energy Transfer, a powerful microscopy method for the detection of subnanometer conformational changes, protein-protein interactions, and protein biochemical status. However, careful quantitative analysis is required for the correct and meaningful interpretation of fluorescence lifetime data. This can be a daunting task to the nonexpert user, and is the source for many avoidable errors and unsound interpretations. Digman and colleagues (Digman et al., 2007, Biophys. J. 94, L14-6) present an analysis technique that avoids data fitting in favor of a simple graphical polar data representation. In this "phasor" space, the physics of lifetime imaging becomes more intuitive and accessible also to the inexperienced user. The cumulated information from image pixels, even over different cells, describes patterns and trajectories that can be visually interpreted in physically meaningful ways. Its usefulness is demonstrated in the study of the dimerization of the uPAR receptor (Caiolfa et al., 2007, J. Cell Biol. 179, 1067-1082).
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Affiliation(s)
- Fred S. Wouters
- Laboratory for Molecular and Cellular Systems, Department of Neuro- and Sensory Physiology, Institute for Physiology and Pathophysiology, University Medicine Göttingen, and the Center for Molecular Physiology of the Brain, Humboldtallee 23, 37073 Göttingen, Germany
| | - Alessandro Esposito
- Laser Analytics Group, Department of Chemical Engineering, University of Cambridge, New Museums Site, Pembroke, CB2 3RA, Cambridge, United Kingdom
- Physiological Laboratory, Department of Physiology, Development and Neuroscience,University of Cambridge, Downing Street, CB2 3EG, Cambridge, United Kingdom
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