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Fernández A, Classen A, Josyula N, Florence JT, Sokolov AV, Scully MO, Straight P, Verhoef AJ. Simultaneous Two- and Three-Photon Deep Imaging of Autofluorescence in Bacterial Communities. SENSORS (BASEL, SWITZERLAND) 2024; 24:667. [PMID: 38276359 PMCID: PMC10819415 DOI: 10.3390/s24020667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
The intrinsic fluorescence of bacterial samples has a proven potential for label-free bacterial characterization, monitoring bacterial metabolic functions, and as a mechanism for tracking the transport of relevant components through vesicles. The reduced scattering and axial confinement of the excitation offered by multiphoton imaging can be used to overcome some of the limitations of single-photon excitation (e.g., scattering and out-of-plane photobleaching) to the imaging of bacterial communities. In this work, we demonstrate in vivo multi-photon microscopy imaging of Streptomyces bacterial communities, based on the excitation of blue endogenous fluorophores, using an ultrafast Yb-fiber laser amplifier. Its parameters, such as the pulse energy, duration, wavelength, and repetition rate, enable in vivo multicolor imaging with a single source through the simultaneous two- and three-photon excitation of different fluorophores. Three-photon excitation at 1040 nm allows fluorophores with blue and green emission spectra to be addressed (and their corresponding ultraviolet and blue single-photon excitation wavelengths, respectively), and two-photon excitation at the same wavelength allows fluorophores with yellow, orange, or red emission spectra to be addressed (and their corresponding green, yellow, and orange single-photon excitation wavelengths). We demonstrate that three-photon excitation allows imaging over a depth range of more than 6 effective attenuation lengths to take place, corresponding to an 800 micrometer depth of imaging, in samples with a high density of fluorescent structures.
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Affiliation(s)
- Alma Fernández
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA;
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA; (A.V.S.); (M.O.S.)
| | - Anton Classen
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA;
| | - Nityakalyani Josyula
- Department of Biochemistry and Biophysics, Texas A&M University, TAMU 2128, College Station, TX 77843, USA; (N.J.); (P.S.)
| | - James T. Florence
- Department of Physics & Astronomy, Texas A&M University, TAMU 4242, College Station, TX 77843, USA;
| | - Alexei V. Sokolov
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA; (A.V.S.); (M.O.S.)
- Department of Physics & Astronomy, Texas A&M University, TAMU 4242, College Station, TX 77843, USA;
| | - Marlan O. Scully
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA; (A.V.S.); (M.O.S.)
| | - Paul Straight
- Department of Biochemistry and Biophysics, Texas A&M University, TAMU 2128, College Station, TX 77843, USA; (N.J.); (P.S.)
| | - Aart J. Verhoef
- Department of Soil and Crop Sciences, Texas A&M University, TAMU 2474, College Station, TX 77843, USA;
- Institute for Quantum Science & Engineering, Texas A&M University, TAMU 4242, College Station, TX 77843, USA; (A.V.S.); (M.O.S.)
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Hernández IC, Yau J, Rishøj L, Cui N, Minderler S, Jowett N. Tutorial: multiphoton microscopy to advance neuroscience research. Methods Appl Fluoresc 2023; 11. [PMID: 36753763 DOI: 10.1088/2050-6120/acba66] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 02/08/2023] [Indexed: 02/10/2023]
Abstract
Multiphoton microscopy (MPM) employs ultrafast infrared lasers for high-resolution deep three-dimensional imaging of live biological samples. The goal of this tutorial is to provide a practical guide to MPM imaging for novice microscopy developers and life-science users. Principles of MPM, microscope setup, and labeling strategies are discussed. Use of MPM to achieve unprecedented imaging depth of whole mounted explants and intravital imaging via implantable glass windows of the mammalian nervous system is demonstrated.
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Affiliation(s)
- Iván Coto Hernández
- Surgical Photonics & Engineering Laboratory, Mass Eye and Ear, Harvard Medical School, 243 Charles St, Boston, MA, United States of America
| | - Jenny Yau
- Surgical Photonics & Engineering Laboratory, Mass Eye and Ear, Harvard Medical School, 243 Charles St, Boston, MA, United States of America
| | - Lars Rishøj
- Technical University of Denmark, DTU Electro, Ørsteds Plads 343, 2800 Kgs. Lyngby, Denmark
| | - Nanke Cui
- Surgical Photonics & Engineering Laboratory, Mass Eye and Ear, Harvard Medical School, 243 Charles St, Boston, MA, United States of America
| | - Steven Minderler
- Surgical Photonics & Engineering Laboratory, Mass Eye and Ear, Harvard Medical School, 243 Charles St, Boston, MA, United States of America
| | - Nate Jowett
- Surgical Photonics & Engineering Laboratory, Mass Eye and Ear, Harvard Medical School, 243 Charles St, Boston, MA, United States of America
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Thornton MA, Futia GL, Stockton ME, Ozbay BN, Kilborn K, Restrepo D, Gibson EA, Hughes EG. Characterization of red fluorescent reporters for dual-color in vivo three-photon microscopy. NEUROPHOTONICS 2022; 9:031912. [PMID: 35496497 PMCID: PMC9047442 DOI: 10.1117/1.nph.9.3.031912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Significance: Three-photon (3P) microscopy significantly increases the depth and resolution of in vivo imaging due to decreased scattering and nonlinear optical sectioning. Simultaneous excitation of multiple fluorescent proteins is essential to studying multicellular interactions and dynamics in the intact brain. Aim: We characterized the excitation laser pulses at a range of wavelengths for 3P microscopy, and then explored the application of tdTomato or mScarlet and EGFP for dual-color single-excitation structural 3P imaging deep in the living mouse brain. Approach: We used frequency-resolved optical gating to measure the spectral intensity, phase, and retrieved pulse widths at a range of wavelengths. Then, we performed in vivo single wavelength-excitation 3P imaging in the 1225- to 1360-nm range deep in the mouse cerebral cortex to evaluate the performance of tdTomato or mScarlet in combination with EGFP. Results: We find that tdTomato and mScarlet, expressed in oligodendrocytes and neurons respectively, have a high signal-to-background ratio in the 1300- to 1360-nm range, consistent with enhanced 3P cross-sections. Conclusions: These results suggest that a single excitation wavelength source is advantageous for multiple applications of dual-color brain imaging and highlight the importance of empirical characterization of individual fluorophores for 3P microscopy.
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Affiliation(s)
- Michael A. Thornton
- University of Colorado Anschutz Medical Campus, Department of Cell and Developmental Biology, Aurora, Colorado, United States
- University of Colorado Anschutz Medical Campus, Neuroscience Program, Aurora, Colorado, United States
| | - Gregory L. Futia
- University of Colorado Anschutz Medical Campus, Department of Bioengineering, Aurora, Colorado, United States
| | - Michael E. Stockton
- University of Colorado Anschutz Medical Campus, Department of Cell and Developmental Biology, Aurora, Colorado, United States
- University of Colorado Anschutz Medical Campus, Neuroscience Program, Aurora, Colorado, United States
| | - Baris N. Ozbay
- Intelligent Imaging Innovations (3i), Denver, Colorado, United States
| | - Karl Kilborn
- Intelligent Imaging Innovations (3i), Denver, Colorado, United States
| | - Diego Restrepo
- University of Colorado Anschutz Medical Campus, Department of Cell and Developmental Biology, Aurora, Colorado, United States
- University of Colorado Anschutz Medical Campus, Neuroscience Program, Aurora, Colorado, United States
| | - Emily A. Gibson
- University of Colorado Anschutz Medical Campus, Neuroscience Program, Aurora, Colorado, United States
- University of Colorado Anschutz Medical Campus, Department of Bioengineering, Aurora, Colorado, United States
| | - Ethan G. Hughes
- University of Colorado Anschutz Medical Campus, Department of Cell and Developmental Biology, Aurora, Colorado, United States
- University of Colorado Anschutz Medical Campus, Neuroscience Program, Aurora, Colorado, United States
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