1
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Shi J, Bera K, Mukherjee P, Alex A, Chaney EJ, Spencer-Dene B, Majer J, Marjanovic M, Spillman DR, Hood SR, Boppart SA. Weakly Supervised Identification and Localization of Drug Fingerprints Based on Label-Free Hyperspectral CARS Microscopy. Anal Chem 2023. [PMID: 37450658 PMCID: PMC10372874 DOI: 10.1021/acs.analchem.3c00979] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Understanding drug fingerprints in complex biological samples is essential for the development of a drug. Hyperspectral coherent anti-Stokes Raman scattering (HS-CARS) microscopy, a label-free nondestructive chemical imaging technique, can profile biological samples based on their endogenous vibrational contrast. Here, we propose a deep learning-assisted HS-CARS imaging approach for the investigation of drug fingerprints and their localization at single-cell resolution. To identify and localize drug fingerprints in complex biological systems, an attention-based deep neural network, hyperspectral attention net (HAN), was developed. By formulating the task to a multiple instance learning problem, HAN highlights informative regions through the attention mechanism when being trained on whole-image labels. Using the proposed technique, we investigated the drug fingerprints of a hepatitis B virus therapy in murine liver tissues. With the increase in drug dosage, higher classification accuracy was observed, with an average area under the curve (AUC) of 0.942 for the high-dose group. Besides, highly informative tissue structures predicted by HAN demonstrated a high degree of similarity with the drug localization shown by the in situ hybridization staining results. These results demonstrate the potential of the proposed deep learning-assisted optical imaging technique for the label-free profiling, identification, and localization of drug fingerprints in biological samples, which can be extended to nonperturbative investigations of complex biological systems under various biological conditions.
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Affiliation(s)
- Jindou Shi
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Kajari Bera
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Prabuddha Mukherjee
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Aneesh Alex
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- In vitro/In vivo Translation, Research, GSK, Collegeville, Pennsylvania 19426, United States
| | - Eric J Chaney
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | | | - Jan Majer
- In vitro/In vivo Translation, Research, GSK, Stevenage SG1 2NY, U.K
| | - Marina Marjanovic
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Darold R Spillman
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Steve R Hood
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- In vitro/In vivo Translation, Research, GSK, Stevenage SG1 2NY, U.K
| | - Stephen A Boppart
- GSK Center for Optical Molecular Imaging, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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2
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Almagro-Ruiz A, Torres-Peiró S, Muñoz-Marco H, Cunquero M, Castro-Olvera G, Dauliat R, Jamier R, Shulika OV, Romero R, Guerreiro PT, Miranda M, Crespo H, Roy P, Loza-Álvarez P, Pérez-Millán P. Few-cycle all-fiber supercontinuum laser for ultrabroadband multimodal nonlinear microscopy. OPTICS EXPRESS 2022; 30:29044-29062. [PMID: 36299089 DOI: 10.1364/oe.454726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 07/15/2022] [Indexed: 06/16/2023]
Abstract
Temporally coherent supercontinuum sources constitute an attractive alternative to bulk crystal-based sources of few-cycle light pulses. We present a monolithic fiber-optic configuration for generating transform-limited temporally coherent supercontinuum pulses with central wavelength at 1.06 µm and duration as short as 13.0 fs (3.7 optical cycles). The supercontinuum is generated by the action of self-phase modulation and optical wave breaking when pumping an all-normal dispersion photonic crystal fiber with pulses of hundreds of fs duration produced by all-fiber chirped pulsed amplification. Avoidance of free-space propagation between stages confers unequalled robustness, efficiency and cost-effectiveness to this novel configuration. Collectively, the features of all-fiber few-cycle pulsed sources make them powerful tools for applications benefitting from the ultrabroadband spectra and ultrashort pulse durations. Here we exploit these features and the deep penetration of light in biological tissues at the spectral region of 1 µm, to demonstrate their successful performance in ultrabroadband multispectral and multimodal nonlinear microscopy.
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3
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Hou Y, Li J, Li B, Yuan Q, Gan W. Combined Second Harmonic Generation and Fluorescence Analyses of the Structures and Dynamics of Molecules on Lipids Using Dual-Probes: A Review. Molecules 2022; 27:molecules27123778. [PMID: 35744902 PMCID: PMC9231091 DOI: 10.3390/molecules27123778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 01/25/2023] Open
Abstract
Revealing the structures and dynamic behaviors of molecules on lipids is crucial for understanding the mechanism behind the biophysical processes, such as the preparation and application of drug delivery vesicles. Second harmonic generation (SHG) has been developed as a powerful tool to investigate the molecules on various lipid membranes, benefiting from its natural property of interface selectivity, which comes from the principle of even order nonlinear optics. Fluorescence emission, which is in principle not interface selective but varies with the chemical environment where the chromophores locate, can reveal the dynamics of molecules on lipids. In this contribution, we review some examples, which are mainly from our recent works focusing on the application of combined spectroscopic methods, i.e., SHG and two-photon fluorescence (TPF), in studying the dynamic behaviors of several dyes or drugs on lipids and surfactants. This review demonstrates that molecules with both SHG and TPF efficiencies may be used as intrinsic dual-probes in plotting a clear physical picture of their own behaviors, as well as the dynamics of other molecules, on lipid membranes.
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Affiliation(s)
- Yi Hou
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, China; (Y.H.); (J.L.); (B.L.)
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Jianhui Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, China; (Y.H.); (J.L.); (B.L.)
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Bifei Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, China; (Y.H.); (J.L.); (B.L.)
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Qunhui Yuan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, China;
| | - Wei Gan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, China; (Y.H.); (J.L.); (B.L.)
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
- Correspondence:
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4
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Boorman D, Pope I, Masia F, Langbein W, Hood S, Borri P, Watson P. Hyperspectral CARS microscopy and quantitative unsupervised analysis of deuterated and non-deuterated fatty acid storage in human cells. J Chem Phys 2021; 155:224202. [PMID: 34911324 DOI: 10.1063/5.0065950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Coherent anti-Stokes Raman scattering (CARS) implemented as a vibrational micro-spectroscopy modality eradicates the need for potentially perturbative fluorescent labeling while still providing high-resolution, chemically specific images of biological samples. Isotopic substitution of hydrogen atoms with deuterium introduces minimal change to molecular structures and can be coupled with CARS microscopy to increase chemical contrast. Here, we investigate HeLa cells incubated with non-deuterated or deuterium-labeled fatty acids, using an in-house-developed hyperspectral CARS microscope coupled with an unsupervised quantitative data analysis algorithm, to retrieve Raman susceptibility spectra and concentration maps of chemical components in physically meaningful units. We demonstrate that our unsupervised analysis retrieves the susceptibility spectra of the specific fatty acids, both deuterated and non-deuterated, in good agreement with reference Raman spectra measured in pure lipids. Our analysis, using the cell-silent spectral region, achieved excellent chemical specificity despite having no prior knowledge and considering the complex intracellular environment inside cells. The quantitative capabilities of the analysis allowed us to measure the concentration of deuterated and non-deuterated fatty acids stored within cytosolic lipid droplets over a 24 h period. Finally, we explored the potential use of deuterium-labeled lipid droplets for non-invasive cell tracking, demonstrating an effective application of the technique for distinguishing between cells in a mixed population over a 16 h period. These results further demonstrate the chemically specific capabilities of hyperspectral CARS microscopy to characterize and distinguish specific lipid types inside cells using an unbiased quantitative data analysis methodology.
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Affiliation(s)
- Dale Boorman
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Iestyn Pope
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Francesco Masia
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Wolfgang Langbein
- School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, United Kingdom
| | - Steve Hood
- GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Paola Borri
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Peter Watson
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
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5
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Müller N, Nicolai F, Buckup T. Broadband mid-infrared phase retrieval for nonlinear microscopy. OPTICS LETTERS 2021; 46:5012-5015. [PMID: 34598255 DOI: 10.1364/ol.440344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Spectral phase characterization of ultrashort laser pulses is essential in nonlinear micro-spectroscopy. Whereas in many applications phases are determined for near-infrared (NIR) pulses, successful mid-infrared (MIR) phase retrieval is rare. The spectral phase of ultra-broadband MIR pulses is determined over more than 1000cm-1 in the presented work. This is accomplished by exploiting the d-scan method in two variants. Both allow for detecting high signals by using the interaction of the MIR and NIR pulses. The two variants differ in imprinting the dispersion. While the dual d-scan imprints phases on both pulses, the Xd-scan method disperses the NIR pulses solely.
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6
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Boorman D, Pope I, Masia F, Watson P, Borri P, Langbein W. Quantification of the nonlinear susceptibility of the hydrogen and deuterium stretch vibration for biomolecules in coherent Raman micro-spectroscopy. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2021; 52:1540-1551. [PMID: 36339900 PMCID: PMC9627839 DOI: 10.1002/jrs.6164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/12/2021] [Accepted: 05/16/2021] [Indexed: 06/14/2023]
Abstract
Deuterium labelling is increasingly used in coherent Raman imaging of complex systems, such as biological cells and tissues, to improve chemical specificity. Nevertheless, quantitative coherent Raman susceptibility spectra for deuterated compounds have not been previously reported. Interestingly, it is expected theoretically that -D stretch vibrations have a Raman susceptibility lower than -H stretch vibrations, with the area of their imaginary part scaling with their wavenumber, which is shifted from around 2900 cm-1 for C-H into the silent region around 2100 cm-1 for C-D. Here, we report quantitative measurements of the nonlinear susceptibility of water, succinic acid, oleic acid, linoleic acid and deuterated isoforms. We show that the -D stretch vibration has indeed a lower area, consistent with the frequency reduction due to the doubling of atomic mass from hydrogen to deuterium. This finding elucidates an important trade-off between chemical specificity and signal strength in the adoption of deuterium labelling as an imaging strategy for coherent Raman microscopy.
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Affiliation(s)
- Dale Boorman
- School of BiosciencesCardiff UniversityCardiffUK
| | - Iestyn Pope
- School of BiosciencesCardiff UniversityCardiffUK
| | | | - Peter Watson
- School of BiosciencesCardiff UniversityCardiffUK
| | - Paola Borri
- School of BiosciencesCardiff UniversityCardiffUK
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7
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Chen T, Yavuz A, Wang MC. Dissecting lipid droplet biology with coherent Raman scattering microscopy. J Cell Sci 2021; 135:261811. [PMID: 33975358 DOI: 10.1242/jcs.252353] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipid droplets (LDs) are lipid-rich organelles universally found in most cells. They serve as a key energy reservoir, actively participate in signal transduction and dynamically communicate with other organelles. LD dysfunction has been associated with a variety of diseases. The content level, composition and mobility of LDs are crucial for their physiological and pathological functions, and these different parameters of LDs are subject to regulation by genetic factors and environmental inputs. Coherent Raman scattering (CRS) microscopy utilizes optical nonlinear processes to probe the intrinsic chemical bond vibration, offering label-free, quantitative imaging of lipids in vivo with high chemical specificity and spatiotemporal resolution. In this Review, we provide an overview over the principle of CRS microscopy and its application in tracking different parameters of LDs in live cells and organisms. We also discuss the use of CRS microscopy in genetic screens to discover lipid regulatory mechanisms and in understanding disease-related lipid pathology.
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Affiliation(s)
- Tao Chen
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ahmet Yavuz
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
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8
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Pope I, Masia F, Ewan K, Jimenez-Pascual A, Dale TC, Siebzehnrubl FA, Borri P, Langbein W. Identifying subpopulations in multicellular systems by quantitative chemical imaging using label-free hyperspectral CARS microscopy. Analyst 2021; 146:2277-2291. [PMID: 33617612 PMCID: PMC8359792 DOI: 10.1039/d0an02381g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/10/2021] [Indexed: 12/21/2022]
Abstract
Quantitative hyperspectral coherent Raman scattering microscopy merges imaging with spectroscopy and utilises quantitative data analysis algorithms to extract physically meaningful chemical components, spectrally and spatially-resolved, with sub-cellular resolution. This label-free non-invasive method has the potential to significantly advance our understanding of the complexity of living multicellular systems. Here, we have applied an in-house developed hyperspectral coherent anti-Stokes Raman scattering (CARS) microscope, combined with a quantitative data analysis pipeline, to imaging living mouse liver organoids as well as fixed mouse brain tissue sections xenografted with glioblastoma cells. We show that the method is capable of discriminating different cellular sub-populations, on the basis of their chemical content which is obtained from an unsupervised analysis, i.e. without prior knowledge. Specifically, in the organoids, we identify sub-populations of cells at different phases in the cell cycle, while in the brain tissue, we distinguish normal tissue from cancer cells, and, notably, tumours derived from transplanted cancer stem cells versus non-stem glioblastoma cells. The ability of the method to identify different sub-populations was validated by correlative fluorescence microscopy using fluorescent protein markers. These examples expand the application portfolio of quantitative chemical imaging by hyperspectral CARS microscopy to multicellular systems of significant biomedical relevance, pointing the way to new opportunities in non-invasive disease diagnostics.
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Affiliation(s)
- Iestyn Pope
- Cardiff University, School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Francesco Masia
- Cardiff University, School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Kenneth Ewan
- Cardiff University, School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Ana Jimenez-Pascual
- Cardiff University, School of Biosciences, European Cancer Stem Cell Research Institute, Hadyn Ellis Building, Maindy Rd, Cardiff CF24 4HQ, UK
| | - Trevor C Dale
- Cardiff University, School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Florian A Siebzehnrubl
- Cardiff University, School of Biosciences, European Cancer Stem Cell Research Institute, Hadyn Ellis Building, Maindy Rd, Cardiff CF24 4HQ, UK
| | - Paola Borri
- Cardiff University, School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Wolfgang Langbein
- Cardiff University, School of Physics & Astronomy, The Parade, Cardiff CF24 3AA, UK.
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9
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Nahmad-Rohen A, Regan D, Masia F, McPhee C, Pope I, Langbein W, Borri P. Quantitative Label-Free Imaging of Lipid Domains in Single Bilayers by Hyperspectral Coherent Raman Scattering. Anal Chem 2020; 92:14657-14666. [PMID: 33090767 PMCID: PMC7660592 DOI: 10.1021/acs.analchem.0c03179] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lipid phase separation in cellular membranes is thought to play an important role in many biological functions. This has prompted the development of synthetic membranes to study lipid-lipid interactions in vitro, alongside optical microscopy techniques aimed at directly visualizing phase partitioning. In this context, there is a need to overcome the limitations of fluorescence microscopy, where added fluorophores can significantly perturb lipid packing. Raman-based optical imaging is a promising analytical tool for label-free chemically specific microscopy of lipid bilayers. In this work, we demonstrate the application of hyperspectral coherent Raman scattering microscopy combined with a quantitative unsupervised data analysis methodology developed in-house to visualize lipid partitioning in single planar membrane bilayers exhibiting liquid-ordered and liquid-disordered domains. Two home-built instruments were utilized, featuring coherent anti-Stokes Raman scattering and stimulated Raman scattering modalities. Ternary mixtures of dioleoylphosphatidylcholine, sphingomyelin, and cholesterol were used to form phase-separated domains. We show that domains are consistently resolved, both chemically and spatially, in a completely label-free manner. Quantitative Raman susceptibility spectra of the domains are provided alongside their spatially resolved concentration maps.
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Affiliation(s)
| | - David Regan
- School of Physics & Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, U.K
| | - Francesco Masia
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, U.K
| | - Craig McPhee
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, U.K
| | - Iestyn Pope
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, U.K
| | - Wolfgang Langbein
- School of Physics & Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, U.K
| | - Paola Borri
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, U.K
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10
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Parodi V, Jacchetti E, Osellame R, Cerullo G, Polli D, Raimondi MT. Nonlinear Optical Microscopy: From Fundamentals to Applications in Live Bioimaging. Front Bioeng Biotechnol 2020; 8:585363. [PMID: 33163482 PMCID: PMC7581943 DOI: 10.3389/fbioe.2020.585363] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/16/2020] [Indexed: 12/13/2022] Open
Abstract
A recent challenge in the field of bioimaging is to image vital, thick, and complex tissues in real time and in non-invasive mode. Among the different tools available for diagnostics, nonlinear optical (NLO) multi-photon microscopy allows label-free non-destructive investigation of physio-pathological processes in live samples at sub-cellular spatial resolution, enabling to study the mechanisms underlying several cellular functions. In this review, we discuss the fundamentals of NLO microscopy and the techniques suitable for biological applications, such as two-photon excited fluorescence (TPEF), second and third harmonic generation (SHG-THG), and coherent Raman scattering (CRS). In addition, we present a few of the most recent examples of NLO imaging employed as a label-free diagnostic instrument to functionally monitor in vitro and in vivo vital biological specimens in their unperturbed state, highlighting the technological advantages of multi-modal, multi-photon NLO microscopy and the outstanding challenges in biomedical engineering applications.
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Affiliation(s)
- Valentina Parodi
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Milan, Italy
| | - Emanuela Jacchetti
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Milan, Italy
| | - Roberto Osellame
- Istituto di Fotonica e Nanotecnologie (IFN) – CNR, Milan, Italy
- Department of Physics, Politecnico di Milano, Milan, Italy
| | - Giulio Cerullo
- Istituto di Fotonica e Nanotecnologie (IFN) – CNR, Milan, Italy
- Department of Physics, Politecnico di Milano, Milan, Italy
| | - Dario Polli
- Istituto di Fotonica e Nanotecnologie (IFN) – CNR, Milan, Italy
- Department of Physics, Politecnico di Milano, Milan, Italy
| | - Manuela Teresa Raimondi
- Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Milan, Italy
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11
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Sinjab F, Hashimoto K, Badarla VR, Omachi J, Ideguchi T. Multimodal laser-scanning nonlinear optical microscope with a rapid broadband Fourier-transform coherent Raman modality. OPTICS EXPRESS 2020; 28:20794-20807. [PMID: 32680132 DOI: 10.1364/oe.397521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Nonlinear optical microscopy allows for rapid high-resolution microscopy with image contrast generated from the intrinsic properties of the sample. Established modalities, such as multiphoton excited fluorescence and second/third-harmonic generation, can be combined with other nonlinear techniques, such as coherent Raman spectroscopy, which typically allow chemical imaging of a single resonant vibrational mode of a sample. Here, we utilize a single ultrafast laser source to obtain broadband coherent Raman spectra on a microscope, together with other nonlinear microscopy approaches on the same instrument. We demonstrate that the coherent Raman modality allows broadband measurement (>1000 cm-1), with high spectral resolution (<5 cm-1), with a rapid spectral acquisition rate (3-12 kHz). This enables Raman hyperspectral imaging of kilo-pixel images at >11 frames per second.
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12
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Lloyd D, Millet CO, Williams CF, Hayes AJ, Pope SJA, Pope I, Borri P, Langbein W, Olsen LF, Isaacs MD, Lunding A. Functional imaging of a model unicell: Spironucleus vortens as an anaerobic but aerotolerant flagellated protist. Adv Microb Physiol 2020; 76:41-79. [PMID: 32408947 DOI: 10.1016/bs.ampbs.2020.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Advances in optical microscopy are continually narrowing the chasm in our appreciation of biological organization between the molecular and cellular levels, but many practical problems are still limiting. Observation is always limited by the rapid dynamics of ultrastructural modifications of intracellular components, and often by cell motility: imaging of the unicellular protist parasite of ornamental fish, Spironucleus vortens, has proved challenging. Autofluorescence of nicotinamide nucleotides and flavins in the 400-580 nm region of the visible spectrum, is the most useful indicator of cellular redox state and hence vitality. Fluorophores emitting in the red or near-infrared (i.e., phosphors) are less damaging and more penetrative than many routinely employed fluors. Mountants containing free radical scavengers minimize fluorophore photobleaching. Two-photon excitation provides a small focal spot, increased penetration, minimizes photon scattering and enables extended observations. Use of quantum dots clarifies the competition between endosomal uptake and exosomal extrusion. Rapid motility (161 μm/s) of the organism makes high resolution of ultrastructure difficult even at high scan speeds. Use of voltage-sensitive dyes determining transmembrane potentials of plasma membrane and hydrogenosomes (modified mitochondria) is also hindered by intracellular motion and controlled anesthesia perturbs membrane organization. Specificity of luminophore binding is always questionable; e.g. cationic lipophilic species widely used to measure membrane potentials also enter membrane-bounded neutral lipid droplet-filled organelles. This appears to be the case in S. vortens, where Coherent Anti-Stokes Raman Scattering (CARS) micro-spectroscopy unequivocally images the latter and simultaneous provides spectral identification at 2840 cm-1. Secondary Harmonic Generation highlights the highly ordered structure of the flagella.
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Affiliation(s)
- David Lloyd
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom; School of Engineering, Cardiff, Wales, United Kingdom
| | - Coralie O Millet
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | | | - Anthony J Hayes
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Simon J A Pope
- School of Chemistry, Main Building, Cardiff University, Cardiff, Wales, United Kingdom
| | - Iestyn Pope
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Paola Borri
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Wolfgang Langbein
- School of Physics and Astronomy, Cardiff University, Cardiff, Wales, United Kingdom
| | - Lars Folke Olsen
- Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Marc D Isaacs
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Anita Lunding
- Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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13
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Bradley J, Pope I, Wang Y, Langbein W, Borri P, Swann K. Dynamic label-free imaging of lipid droplets and their link to fatty acid and pyruvate oxidation in mouse eggs. J Cell Sci 2019; 132:jcs.228999. [PMID: 31182643 DOI: 10.1242/jcs.228999] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 05/28/2019] [Indexed: 11/20/2022] Open
Abstract
Mammalian eggs generate most of their ATP by mitochondrial oxidation of pyruvate from the surrounding medium or from fatty acids that are stored as triacylglycerols within lipid droplets. The balance between pyruvate and fatty acid oxidation in generating ATP is not established. We have combined coherent anti-Stokes Raman scattering (CARS) imaging with deuterium labelling of oleic acid to monitor turnover of fatty acids within lipid droplets of living mouse eggs. We found that loss of labelled oleic acid is promoted by pyruvate removal but minimised when β-oxidation is inhibited. Pyruvate removal also causes a significant dispersion of lipid droplets, while inhibition of β-oxidation causes droplet clustering. Live imaging of luciferase or FAD autofluorescence from mitochondria, suggest that inhibition of β-oxidation in mouse eggs only leads to a transient decrease in ATP because there is compensatory uptake of pyruvate into mitochondria. Inhibition of pyruvate uptake followed by β-oxidation caused a similar and successive decline in ATP. Our data suggest that β-oxidation and pyruvate oxidation contribute almost equally to resting ATP production in resting mouse eggs and that reorganisation of lipid droplets occurs in response to metabolic demand.
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Affiliation(s)
- Josephine Bradley
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
| | - Iestyn Pope
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
| | - Yisu Wang
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
| | - Wolfgang Langbein
- School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA
| | - Paola Borri
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
| | - Karl Swann
- School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
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14
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Watts KE, Blackburn TJ, Pemberton JE. Optical Spectroscopy of Surfaces, Interfaces, and Thin Films: A Status Report. Anal Chem 2019; 91:4235-4265. [PMID: 30790520 DOI: 10.1021/acs.analchem.9b00735] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kristen E Watts
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
| | - Thomas J Blackburn
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
| | - Jeanne E Pemberton
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
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15
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Maibohm C, Silva F, Figueiras E, Guerreiro PT, Brito M, Romero R, Crespo H, Nieder JB. SyncRGB-FLIM: synchronous fluorescence imaging of red, green and blue dyes enabled by ultra-broadband few-cycle laser excitation and fluorescence lifetime detection. BIOMEDICAL OPTICS EXPRESS 2019; 10:1891-1904. [PMID: 31086710 PMCID: PMC6484984 DOI: 10.1364/boe.10.001891] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate for the first time that an ultra-broadband 7 femtosecond (fs) few-cycle laser can be used for multicolor nonlinear imaging in a single channel detection geometry, when employing a time-resolved fluorescence detection scheme. On a multi-chromophore-labelled cell sample we show that the few-cycle laser can efficiently excite the multiple chromophores over a >400 nm two-photon absorption range. By combining the few-cycle laser excitation with time-correlated single-photon counting (TCSPC) detection to record two-photon fluorescence lifetime imaging microscopy (FLIM) images, the localization of different chromophores in the cell can be identified based on their fluorescence decay properties. The novel SyncRGB-FLIM multi-color bioimaging technique opens the possibility of real-time protein-protein interaction studies, where its single-scan operation translates into reduced laser exposure of the sample, resulting in more photoprotective conditions for biological specimens.
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Affiliation(s)
- Christian Maibohm
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
| | - Francisco Silva
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
| | - Edite Figueiras
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
- Present address: Fundação Champalimaud, Avenida Brasília, 1400-038 Lisboa, Portugal
| | - Paulo T. Guerreiro
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Marina Brito
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
| | - Rosa Romero
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Helder Crespo
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Jana B. Nieder
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
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16
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Karuna A, Masia F, Wiltshire M, Errington R, Borri P, Langbein W. Label-Free Volumetric Quantitative Imaging of the Human Somatic Cell Division by Hyperspectral Coherent Anti-Stokes Raman Scattering. Anal Chem 2019; 91:2813-2821. [PMID: 30624901 DOI: 10.1021/acs.analchem.8b04706] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Quantifying the chemical composition of unstained intact tissue and cellular samples with high spatio-temporal resolution in three dimensions would provide a step change in cell and tissue analytics critical to progress the field of cell biology. Label-free optical microscopy offers the required resolution and noninvasiveness, yet quantitative imaging with chemical specificity is a challenging endeavor. In this work, we show that hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy can be used to provide quantitative volumetric imaging of human osteosarcoma cells at various stages through cell division, a fundamental component of the cell cycle progress resulting in the segregation of cellular content to produce two progeny. We have developed and applied a quantitative data analysis method to produce volumetric three-dimensional images of the chemical composition of the dividing cell in terms of water, proteins, DNAP (a mixture of proteins and DNA, similar to chromatin), and lipids. We then used these images to determine the dry masses of the corresponding organic components. The attribution of proteins and DNAP components was validated using specific well-characterized fluorescent probes, by comparison with correlative two-photon fluorescence microscopy of DNA and mitochondria. Furthermore, we map the same chemical components under perturbed conditions, employing a drug that interferes directly with cell division (Taxol), showing its influence on cell organization and the masses of proteins, DNAP, and lipids.
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Affiliation(s)
- Arnica Karuna
- School of Physics and Astronomy , Cardiff University , The Parade , Cardiff CF24 3AA , United Kingdom
| | - Francesco Masia
- School of Physics and Astronomy , Cardiff University , The Parade , Cardiff CF24 3AA , United Kingdom
| | - Marie Wiltshire
- Division of Cancer and Genetics, School of Medicine , Cardiff University , Heath Park , Cardiff CF14 4XN , United Kingdom
| | - Rachel Errington
- Division of Cancer and Genetics, School of Medicine , Cardiff University , Heath Park , Cardiff CF14 4XN , United Kingdom
| | - Paola Borri
- School of Biosciences , Cardiff University , Museum Avenue , Cardiff CF10 3AX , United Kingdom
| | - Wolfgang Langbein
- School of Physics and Astronomy , Cardiff University , The Parade , Cardiff CF24 3AA , United Kingdom
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17
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Masia F, Glen A, Stephens P, Langbein W, Borri P. Label-free quantitative chemical imaging and classification analysis of adipogenesis using mouse embryonic stem cells. JOURNAL OF BIOPHOTONICS 2018; 11:e201700219. [PMID: 29573183 DOI: 10.1002/jbio.201700219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Stem cells have received much attention recently for their potential utility in regenerative medicine. The identification of their differentiated progeny often requires complex staining procedures, and is challenging for intermediary stages which are a priori unknown. In this work, the ability of label-free quantitative coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy to identify populations of intermediate cell states during the differentiation of murine embryonic stem cells into adipocytes is assessed. Cells were imaged at different days of differentiation by hyperspectral CARS, and images were analysed with an unsupervised factorization algorithm providing Raman-like spectra and spatially resolved maps of chemical components. Chemical decomposition combined with a statistical analysis of their spatial distributions provided a set of parameters that were used for classification analysis. The first 2 principal components of these parameters indicated 3 main groups, attributed to undifferentiated cells, cells differentiated into committed white pre-adipocytes, and differentiating cells exhibiting a distinct protein globular structure with adjacent lipid droplets. An unsupervised classification methodology was developed, separating undifferentiated cell from cells in other stages, using a novel method to estimate the optimal number of clusters. The proposed unsupervised classification pipeline of hyperspectral CARS data offers a promising new tool for automated cell sorting in lineage analysis.
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Affiliation(s)
- Francesco Masia
- School of Physics and Astronomy, Cardiff University, Cardiff, UK
| | - Adam Glen
- School of Dentistry, Cardiff University, Cardiff, UK
| | - Phil Stephens
- School of Dentistry, Cardiff University, Cardiff, UK
| | | | - Paola Borri
- School of Biosciences, Cardiff University, Cardiff, UK
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18
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Masia F, Pope I, Watson P, Langbein W, Borri P. Bessel-Beam Hyperspectral CARS Microscopy with Sparse Sampling: Enabling High-Content High-Throughput Label-Free Quantitative Chemical Imaging. Anal Chem 2018; 90:3775-3785. [PMID: 29505230 DOI: 10.1021/acs.analchem.7b04039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Microscopy-based high-content and high-throughput analysis of cellular systems plays a central role in drug discovery. However, for contrast and specificity, the majority of assays require a fluorescent readout which always comes with the risk of alteration of the true biological conditions. In this work, we demonstrate a label-free imaging platform which combines chemically specific hyperspectral coherent anti-Stokes Raman scattering microscopy with sparse sampling and Bessel beam illumination. This enabled us to screen multiwell plates at high speed, while retaining the high-content chemical analysis of hyperspectral imaging. To demonstrate the practical applicability of the method we addressed a critical side effect in drug screens, namely, drug-induced lipid storage within hepatic tissue. We screened 15 combinations of drugs and neutral lipids added to human HepG2 liver cells and developed a high-content quantitative data analysis pipeline which extracted the spectra and spatial distributions of lipid and protein components. We then used their combination to train a support vector machine discriminative algorithm. Classification of the drug responses in terms of phospholipidosis versus steatosis was achieved in a completely label-free assay.
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Affiliation(s)
- Francesco Masia
- School of Physics and Astronomy , Cardiff University , The Parade , Cardiff CF24 3AA , U.K
| | - Iestyn Pope
- School of Biosciences , Cardiff University , Museum Avenue , Cardiff CF10 3AX , U.K
| | - Peter Watson
- School of Biosciences , Cardiff University , Museum Avenue , Cardiff CF10 3AX , U.K
| | - Wolfgang Langbein
- School of Physics and Astronomy , Cardiff University , The Parade , Cardiff CF24 3AA , U.K
| | - Paola Borri
- School of Biosciences , Cardiff University , Museum Avenue , Cardiff CF10 3AX , U.K
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19
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Porquez JG, Cole RA, Tabarangao JT, Slepkov AD. Brighter CARS hypermicroscopy via "spectral surfing" of a Stokes supercontinuum. OPTICS LETTERS 2017; 42:2255-2258. [PMID: 28614325 DOI: 10.1364/ol.42.002255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
We present a simple technique that significantly enhances the interaction of pump pulses with a supercontinuum Stokes generated by a particular nonlinear fiber for time-gated experiments such as coherent anti-Stokes Raman scattering (CARS). The enhancement is achieved through a synchronized power-tuning/time delay scheme that we call spectral surfing. In this Letter, we introduce spectral surfing and demonstrate how its application to an economical CARS hypermicroscopy scheme increases the brightness, contrast, and spectral scanning range, while potentially reducing sample light exposure.
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20
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Porquez JG, Cole RA, Tabarangao JT, Slepkov AD. Spectrally-broad coherent anti-Stokes Raman scattering hyper-microscopy utilizing a Stokes supercontinuum pumped at 800 nm. BIOMEDICAL OPTICS EXPRESS 2016; 7:4335-4345. [PMID: 27867735 PMCID: PMC5102551 DOI: 10.1364/boe.7.004335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/16/2016] [Accepted: 09/22/2016] [Indexed: 06/06/2023]
Abstract
We demonstrate spectral-focusing based coherent anti-Stokes Raman scattering (SF-CARS) hyper-microscopy capable of probing vibrational frequencies from 630 cm-1 to 3250 cm-1 using a single Ti:Sapphire femtosecond laser operating at 800 nm, and a commercially-available supercontinuum-generating fibre module. A broad Stokes supercontinuum with significant spectral power at wavelengths between 800 nm and 940 nm is generated by power tuning the fibre module using atypically long and/or chirped ~200 fs pump pulses, allowing convenient access to lower vibrational frequencies in the fingerprint spectral region. This work significantly reduces the instrumental and technical requirements for multimodal CARS microscopy, while expanding the spectral capabilities of an established approach to SF-CARS.
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Affiliation(s)
- Jeremy G. Porquez
- Department of Physics and Astronomy, Trent University, 1600 W Bank Dr., Peterborough, Ontario, K9L 0G2, Canada
| | - Ryan A. Cole
- Department of Physics and Astronomy, Trent University, 1600 W Bank Dr., Peterborough, Ontario, K9L 0G2, Canada
| | - Joel T. Tabarangao
- Department of Physics and Astronomy, Trent University, 1600 W Bank Dr., Peterborough, Ontario, K9L 0G2, Canada
| | - Aaron D. Slepkov
- Department of Physics and Astronomy, Trent University, 1600 W Bank Dr., Peterborough, Ontario, K9L 0G2, Canada
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21
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Krauth J, Steinle T, Liu B, Floess M, Linnenbank H, Steinmann A, Giessen H. Low drift cw-seeded high-repetition-rate optical parametric amplifier for fingerprint coherent Raman spectroscopy. OPTICS EXPRESS 2016; 24:22296-22302. [PMID: 27661963 DOI: 10.1364/oe.24.022296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We introduce a broadly tunable robust source for fingerprint (170 - 1620 cm-1) Raman spectroscopy. A cw thulium-doped fiber laser seeds an optical parametric amplifier, which is pumped by a 7-W, 450-fs Yb:KGW bulk mode-locked oscillator with 41 MHz repetition rate. The output radiation is frequency doubled in a MgO:PPLN crystal and generates 0.7 - 1.3-ps-long narrowband pump pulses that are tunable between 885 and 1015 nm with >80 mW average power. The Stokes beam is delivered by a part of the oscillator output, which is sent through an etalon to create pulses with 1.7 ps duration. We demonstrate a stimulated Raman gain measurement of toluene in the fingerprint spectral range. The cw seeding intrinsically ensures low spectral drift.
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22
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Karuna A, Masia F, Borri P, Langbein W. Hyperspectral volumetric coherent anti-Stokes Raman scattering microscopy: quantitative volume determination and NaCl as non-resonant standard. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2016; 47:1167-1173. [PMID: 27708499 PMCID: PMC5032898 DOI: 10.1002/jrs.4876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/11/2015] [Accepted: 12/11/2015] [Indexed: 06/06/2023]
Abstract
In this work, we demonstrate quantitative volume determination of chemical components in three dimensions using hyperspectral coherent anti-Stokes Raman scattering microscopy, phase-corrected Kramers-Kronig retrieval of the coherent anti-Stokes Raman scattering susceptibility and factorization into concentration of chemical components. We investigate the influence of the refractive index contrast between water and polymer beads (polystyrene and polymethylmethacrylate), showing that it leads mainly to concentration errors, while the spectral error is less affected. The volume of polystyrene beads of sizes from 200 nm to 3 μm is determined with 10% relative error and 1% absolute error in the region of interest. We furthermore establish the use of sodium chloride as non-resonant reference material free of Raman-active vibrational resonances.
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Affiliation(s)
- Arnica Karuna
- School of Physics and Astronomy Cardiff University, The Parade Cardiff CF24 3AA UK
| | - Francesco Masia
- School of Physics and Astronomy Cardiff University, The Parade Cardiff CF24 3AA UK
| | - Paola Borri
- School of Biosciences Cardiff University Museum Avenue Cardiff CF10 3AX UK
| | - Wolfgang Langbein
- School of Physics and Astronomy Cardiff University, The Parade Cardiff CF24 3AA UK
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23
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Bradley J, Pope I, Masia F, Sanusi R, Langbein W, Swann K, Borri P. Quantitative imaging of lipids in live mouse oocytes and early embryos using CARS microscopy. Development 2016; 143:2238-47. [PMID: 27151947 PMCID: PMC4920167 DOI: 10.1242/dev.129908] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 04/27/2016] [Indexed: 02/05/2023]
Abstract
Mammalian oocytes contain lipid droplets that are a store of fatty acids, whose metabolism plays a substantial role in pre-implantation development. Fluorescent staining has previously been used to image lipid droplets in mammalian oocytes and embryos, but this method is not quantitative and often incompatible with live cell imaging and subsequent development. Here we have applied chemically specific, label-free coherent anti-Stokes Raman scattering (CARS) microscopy to mouse oocytes and pre-implantation embryos. We show that CARS imaging can quantify the size, number and spatial distribution of lipid droplets in living mouse oocytes and embryos up to the blastocyst stage. Notably, it can be used in a way that does not compromise oocyte maturation or embryo development. We have also correlated CARS with two-photon fluorescence microscopy simultaneously acquired using fluorescent lipid probes on fixed samples, and found only a partial degree of correlation, depending on the lipid probe, clearly exemplifying the limitation of lipid labelling. In addition, we show that differences in the chemical composition of lipid droplets in living oocytes matured in media supplemented with different saturated and unsaturated fatty acids can be detected using CARS hyperspectral imaging. These results demonstrate that CARS microscopy provides a novel non-invasive method of quantifying lipid content, type and spatial distribution with sub-micron resolution in living mammalian oocytes and embryos.
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Affiliation(s)
- Josephine Bradley
- Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK
| | - Iestyn Pope
- Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK
| | - Francesco Masia
- Cardiff School of Physics and Astronomy, The Parade, Cardiff CF24 3AA, UK
| | - Randa Sanusi
- Cardiff University School of Medicine, Sir Geraint Evans Building, Heath Park, Cardiff CF14 4XN, UK
| | - Wolfgang Langbein
- Cardiff School of Physics and Astronomy, The Parade, Cardiff CF24 3AA, UK
| | - Karl Swann
- Cardiff University School of Medicine, Sir Geraint Evans Building, Heath Park, Cardiff CF14 4XN, UK
| | - Paola Borri
- Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK
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24
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Di Napoli C, Pope I, Masia F, Langbein W, Watson P, Borri P. Quantitative Spatiotemporal Chemical Profiling of Individual Lipid Droplets by Hyperspectral CARS Microscopy in Living Human Adipose-Derived Stem Cells. Anal Chem 2016; 88:3677-85. [DOI: 10.1021/acs.analchem.5b04468] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Claudia Di Napoli
- School
of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Iestyn Pope
- School
of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Francesco Masia
- School
of Physics and Astronomy, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Wolfgang Langbein
- School
of Physics and Astronomy, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Pete Watson
- School
of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Paola Borri
- School
of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
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25
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Klinger A, Krapf L, Orzekowsky-Schroeder R, Koop N, Vogel A, Hüttmann G. Intravital autofluorescence 2-photon microscopy of murine intestinal mucosa with ultra-broadband femtosecond laser pulse excitation: image quality, photodamage, and inflammation. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:116001. [PMID: 26524678 DOI: 10.1117/1.jbo.20.11.116001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Ultra-broadband excitation with ultrashort pulses may enable simultaneous excitation of multiple endogenous fluorophores in vital tissue. Imaging living gut mucosa by autofluorescence 2-photon microscopy with more than 150 nm broad excitation at an 800-nm central wavelength from a sub-10 fs titanium-sapphire (Ti:sapphire) laser with a dielectric mirror based prechirp was compared to the excitation with 220 fs pulses of a tunable Ti:sapphire laser at 730 and 800 nm wavelengths. Excitation efficiency, image quality, and photochemical damage were evaluated. At similar excitation fluxes, the same image brightness was achieved with both lasers. As expected, with ultra-broadband pulses, fluorescence from NAD(P)H, flavines, and lipoproteins was observed simultaneously. However, nonlinear photodamage apparent as hyperfluorescence with functional and structural alterations of the tissue occurred earlier when the laser power was adjusted to the same image brightness. After only a few minutes, the immigration of polymorphonuclear leucocytes into the epithelium and degranulation of these cells, a sign of inflammation, was observed. Photodamage is promoted by the higher peak irradiances and/or by nonoptimal excitation of autofluorescence at the longer wavelength. We conclude that excitation with a tunable narrow bandwidth laser is preferable to ultra-broadband excitation for autofluorescence-based 2-photon microscopy, unless the spectral phase can be controlled to optimize excitation conditions.
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Affiliation(s)
- Antje Klinger
- University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Lisa Krapf
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | | | - Norbert Koop
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | - Alfred Vogel
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | - Gereon Hüttmann
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, GermanycAirway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Germany
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26
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Zeytunyan A, Crampton KT, Zadoyan R, Apkarian VA. Supercontinuum-based three-color three-pulse time-resolved coherent anti-Stokes Raman scattering. OPTICS EXPRESS 2015; 23:24019-24028. [PMID: 26368493 DOI: 10.1364/oe.23.024019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate the use of a photonic crystal fiber (PCF) as a compact three-color fs laser system operating at 76 MHz, limited only by the repetition rate of the pump laser. The system is suitable for background-free time-resolved four-wave mixing measurements, which arguably reach fundamental limits in signal detectivity. We give a detailed characterization of the near transform-limited multi-color pulses that are extracted from the PCF, and prove the system through time-resolved coherent anti-Stokes Raman scattering measurements in bipyridyl ethylene and styrene.
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27
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Masia F, Karuna A, Borri P, Langbein W. Hyperspectral image analysis for CARS, SRS, and Raman data. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2015; 46:727-734. [PMID: 27478301 PMCID: PMC4950149 DOI: 10.1002/jrs.4729] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 05/01/2015] [Accepted: 05/05/2015] [Indexed: 05/23/2023]
Abstract
In this work, we have significantly enhanced the capabilities of the hyperspectral image analysis (HIA) first developed by Masia et al. 1 The HIA introduced a method to factorize the hyperspectral data into the product of component concentrations and spectra for quantitative analysis of the chemical composition of the sample. The enhancements shown here comprise (1) a spatial weighting to reduce the spatial variation of the spectral error, which improves the retrieval of the chemical components with significant local but small global concentrations; (2) a new selection criterion for the spectra used when applying sparse sampling2 to speed up sequential hyperspectral imaging; and (3) a filter for outliers in the data using singular value decomposition, suited e.g. to suppress motion artifacts. We demonstrate the enhancements on coherent anti-Stokes Raman scattering, stimulated Raman scattering, and spontaneous Raman data. We provide the HIA software as executable for public use. © 2015 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Francesco Masia
- School of Physics and Astronomy Cardiff University The Parade Cardiff CF24 3AA UK
| | - Arnica Karuna
- School of Physics and Astronomy Cardiff University The Parade Cardiff CF24 3AA UK
| | - Paola Borri
- School of Physics and Astronomy Cardiff University The Parade Cardiff CF24 3AA UK; School of Biosciences Cardiff University Museum Avenue Cardiff CF10 3AX UK
| | - Wolfgang Langbein
- School of Physics and Astronomy Cardiff University The Parade Cardiff CF24 3AA UK
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Pope I, Payne L, Zoriniants G, Thomas E, Williams O, Watson P, Langbein W, Borri P. Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds. NATURE NANOTECHNOLOGY 2014; 9:940-6. [PMID: 25305746 PMCID: PMC4990125 DOI: 10.1038/nnano.2014.210] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 08/14/2014] [Indexed: 05/22/2023]
Abstract
Nanoparticles have attracted enormous attention for biomedical applications as optical labels, drug-delivery vehicles and contrast agents in vivo. In the quest for superior photostability and biocompatibility, nanodiamonds are considered one of the best choices due to their unique structural, chemical, mechanical and optical properties. So far, mainly fluorescent nanodiamonds have been utilized for cell imaging. However, their use is limited by the efficiency and costs in reliably producing fluorescent defect centres with stable optical properties. Here, we show that single non-fluorescing nanodiamonds exhibit strong coherent anti-Stokes Raman scattering (CARS) at the sp(3) vibrational resonance of diamond. Using correlative light and electron microscopy, the relationship between CARS signal strength and nanodiamond size is quantified. The calibrated CARS signal in turn enables the analysis of the number and size of nanodiamonds internalized in living cells in situ, which opens the exciting prospect of following complex cellular trafficking pathways quantitatively.
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Affiliation(s)
- Iestyn Pope
- Cardiff University School of Biosciences, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Lukas Payne
- Cardiff University School of Biosciences, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - George Zoriniants
- Cardiff University School of Biosciences, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Evan Thomas
- Cardiff University School of Physics and Astronomy, The Parade, Cardiff CF24 3AA, United Kingdom
| | - Oliver Williams
- Cardiff University School of Physics and Astronomy, The Parade, Cardiff CF24 3AA, United Kingdom
| | - Peter Watson
- Cardiff University School of Biosciences, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Wolfgang Langbein
- Cardiff University School of Physics and Astronomy, The Parade, Cardiff CF24 3AA, United Kingdom
| | - Paola Borri
- Cardiff University School of Biosciences, Museum Avenue, Cardiff CF10 3AX, United Kingdom
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Di Napoli C, Pope I, Masia F, Watson P, Langbein W, Borri P. Hyperspectral and differential CARS microscopy for quantitative chemical imaging in human adipocytes. BIOMEDICAL OPTICS EXPRESS 2014; 5:1378-90. [PMID: 24877002 PMCID: PMC4026891 DOI: 10.1364/boe.5.001378] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/09/2014] [Accepted: 03/09/2014] [Indexed: 05/10/2023]
Abstract
In this work, we demonstrate the applicability of coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy for quantitative chemical imaging of saturated and unsaturated lipids in human stem-cell derived adipocytes. We compare dual-frequency/differential CARS (D-CARS), which enables rapid imaging and simple data analysis, with broadband hyperspectral CARS microscopy analyzed using an unsupervised phase-retrieval and factorization method recently developed by us for quantitative chemical image analysis. Measurements were taken in the vibrational fingerprint region (1200-2000/cm) and in the CH stretch region (2600-3300/cm) using a home-built CARS set-up which enables hyperspectral imaging with 10/cm resolution via spectral focussing from a single broadband 5 fs Ti:Sa laser source. Through a ratiometric analysis, both D-CARS and phase-retrieved hyperspectral CARS determine the concentration of unsaturated lipids with comparable accuracy in the fingerprint region, while in the CH stretch region D-CARS provides only a qualitative contrast owing to its non-linear behavior. When analyzing hyperspectral CARS images using the blind factorization into susceptibilities and concentrations of chemical components recently demonstrated by us, we are able to determine vol:vol concentrations of different lipid components and spatially resolve inhomogeneities in lipid composition with superior accuracy compared to state-of-the art ratiometric methods.
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Affiliation(s)
| | - Iestyn Pope
- School of Biosciences, Cardiff University, Cardiff CF10 3US,
UK
| | - Francesco Masia
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA,
UK
| | - Peter Watson
- School of Biosciences, Cardiff University, Cardiff CF10 3US,
UK
| | - Wolfgang Langbein
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA,
UK
| | - Paola Borri
- School of Biosciences, Cardiff University, Cardiff CF10 3US,
UK
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30
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Brox D, Schwering M, Engelhardt J, Herten DP. Reversible Chemical Reactions for Single-Color Multiplexing Microscopy. Chemphyschem 2014; 15:2331-6. [DOI: 10.1002/cphc.201402012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Indexed: 11/09/2022]
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Masia F, Borri P, Langbein W. Sparse sampling for fast hyperspectral coherent anti-Stokes Raman scattering imaging. OPTICS EXPRESS 2014; 22:4021-4028. [PMID: 24663723 DOI: 10.1364/oe.22.004021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate a method to increase the acquisition speed in coherent anti-Stokes Raman scattering (CARS) hyperspectral imaging while retaining the relevant spectral information. The method first determines the important spectral components of a sample from a hyper-spectral image over a small number of spatial points but a large number of spectral points covering the accessible spectral range and sampling the instrument spectral resolution at the Nyquist limit. From these components we determine a small set of frequencies needed to retrieve the weights of the components with minimum error for a given measurement noise. Hyperspectral images with a large number of spatial points, for example covering a large spatial region, are then measured at this small set of frequencies, and a reconstruction algorithm is applied to generate the full spectral range and resolution. The resulting spectra are suited to retrieve from the CARS intensity the CARS susceptibility which is linear in the concentration, and apply unsupervised quantitative analysis methods such as FSC3. We demonstrate the method on CARS hyperspectral images of human osteosarcoma U2OS cell, with a reduction in the acquisition time by a factor of 25. This method is suited also for other coherent vibrational microscopy techniques such as stimulated Raman scattering, and in general for hyperspectral imaging techniques with sequential spectral acquisition.
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32
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Masia F, Glen A, Stephens P, Borri P, Langbein W. Quantitative chemical imaging and unsupervised analysis using hyperspectral coherent anti-Stokes Raman scattering microscopy. Anal Chem 2013; 85:10820-8. [PMID: 24099603 PMCID: PMC3889493 DOI: 10.1021/ac402303g] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
![]()
In this work, we report a method
to acquire and analyze hyperspectral
coherent anti-Stokes Raman scattering (CARS) microscopy images of
organic materials and biological samples resulting in an unbiased
quantitative chemical analysis. The method employs singular value
decomposition on the square root of the CARS intensity, providing
an automatic determination of the components above noise, which are
retained. Complex CARS susceptibility spectra, which are linear in
the chemical composition, are retrieved from the CARS intensity spectra
using the causality of the susceptibility by two methods, and their
performance is evaluated by comparison with Raman spectra. We use
non-negative matrix factorization applied to the imaginary part and
the nonresonant real part of the susceptibility with an additional
concentration constraint to obtain absolute susceptibility spectra
of independently varying chemical components and their absolute concentration.
We demonstrate the ability of the method to provide quantitative chemical
analysis on known lipid mixtures. We then show the relevance of the
method by imaging lipid-rich stem-cell-derived mouse adipocytes as
well as differentiated embryonic stem cells with a low density of
lipids. We retrieve and visualize the most significant chemical components
with spectra given by water, lipid, and proteins segmenting the image
into the cell surrounding, lipid droplets, cytosol, and the nucleus,
and we reveal the chemical structure of the cells, with details visualized
by the projection of the chemical contrast into a few relevant channels.
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Affiliation(s)
- Francesco Masia
- School of Physics and Astronomy, Cardiff University , CF24 3AA Cardiff, U.K.
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Zumbusch A, Langbein W, Borri P. Nonlinear vibrational microscopy applied to lipid biology. Prog Lipid Res 2013; 52:615-32. [PMID: 24051337 DOI: 10.1016/j.plipres.2013.07.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/31/2013] [Indexed: 11/15/2022]
Abstract
Optical microscopy is an indispensable tool that is driving progress in cell biology. It still is the only practical means of obtaining spatial and temporal resolution within living cells and tissues. Most prominently, fluorescence microscopy based on dye-labeling or protein fusions with fluorescent tags is a highly sensitive and specific method of visualizing biomolecules within sub-cellular structures. It is however severely limited by labeling artifacts, photo-bleaching and cytotoxicity of the labels. Coherent Raman Scattering (CRS) has emerged in the last decade as a new multiphoton microscopy technique suited for imaging unlabeled living cells in real time with high three-dimensional spatial resolution and chemical specificity. This technique has proven to be particularly successful in imaging unstained lipids from artificial membrane model systems, to living cells and tissues to whole organisms. In this article, we will review the experimental implementations of CRS microscopy and their application to imaging lipids. We will cover the theoretical background of linear and non-linear vibrational micro-spectroscopy necessary for the understanding of CRS microscopy. The different experimental implementations of CRS will be compared in terms of sensitivity limits and excitation and detection methods. Finally, we will provide an overview of the applications of CRS microscopy to lipid biology.
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Affiliation(s)
- Andreas Zumbusch
- Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
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