1
|
Sorrells JE, Iyer RR, Yang L, Bower AJ, Spillman DR, Chaney EJ, Tu H, Boppart SA. Real-time pixelwise phasor analysis for video-rate two-photon fluorescence lifetime imaging microscopy. BIOMEDICAL OPTICS EXPRESS 2021; 12:4003-4019. [PMID: 34457395 PMCID: PMC8367245 DOI: 10.1364/boe.424533] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 05/06/2023]
Abstract
Two-photon fluorescence lifetime imaging microscopy (FLIM) is a widely used technique in biomedical optical imaging. Presently, many two-photon time-domain FLIM setups are limited by long acquisition and postprocessing times that decrease data throughput and inhibit the ability to image fast sub-second processes. Here, we present a versatile two-photon FLIM setup capable of video-rate (up to 25 fps) imaging with graphics processing unit (GPU)-accelerated pixelwise phasor analysis displayed and saved simultaneously with acquisition. The system uses an analog output photomultiplier tube in conjunction with 12-bit digitization at 3.2 GHz to overcome the limited maximum acceptable photon rate associated with the photon counting electronics in many FLIM systems. This allows for higher throughput FLIM acquisition and analysis, and additionally enables the user to assess sample fluorescence lifetime in real-time. We further explore the capabilities of the system to examine the kinetics of Rhodamine B uptake by human breast cancer cells and characterize the effect of pixel dwell time on the reduced nicotinamide adenine dinucleotide and reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) autofluorescence lifetime estimation accuracy.
Collapse
Affiliation(s)
- Janet E. Sorrells
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Rishyashring R. Iyer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Lingxiao Yang
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrew J. Bower
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Darold R. Spillman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eric J. Chaney
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Haohua Tu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center at Illinois, Urbana, IL 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
2
|
Flynn DC, Bhagwat AR, Brenner MH, Núñez MF, Mork BE, Cai D, Swanson JA, Ogilvie JP. Pulse-shaping based two-photon FRET stoichiometry. OPTICS EXPRESS 2015; 23:3353-72. [PMID: 25836193 PMCID: PMC4394757 DOI: 10.1364/oe.23.003353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/09/2015] [Accepted: 01/13/2015] [Indexed: 06/04/2023]
Abstract
Förster Resonance Energy Transfer (FRET) based measurements that calculate the stoichiometry of intermolecular interactions in living cells have recently been demonstrated, where the technique utilizes selective one-photon excitation of donor and acceptor fluorophores to isolate the pure FRET signal. Here, we present work towards extending this FRET stoichiometry method to employ two-photon excitation using a pulse-shaping methodology. In pulse-shaping, frequency-dependent phases are applied to a broadband femtosecond laser pulse to tailor the two-photon excitation conditions to preferentially excite donor and acceptor fluorophores. We have also generalized the existing stoichiometry theory to account for additional cross-talk terms that are non-vanishing under two-photon excitation conditions. Using the generalized theory we demonstrate two-photon FRET stoichiometry in live COS-7 cells expressing fluorescent proteins mAmetrine as the donor and tdTomato as the acceptor.
Collapse
Affiliation(s)
- Daniel C. Flynn
- Macromolecular Science and Engineering, University of Michigan, 2300 Hayward St, Ann Arbor, MI 48109
USA
| | - Amar R. Bhagwat
- Department of Physics, University of Michigan, 450 Church St., Ann Arbor, MI 48109
USA
| | - Meredith H. Brenner
- Applied Physics Program, University of Michigan, 450 Church St., Ann Arbor, MI 48109
USA
| | - Marcos F. Núñez
- Biophysics Program, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109
USA
| | - Briana E. Mork
- Department of Physics, University of Michigan, 450 Church St., Ann Arbor, MI 48109
USA
| | - Dawen Cai
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109
USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109
USA
| | - Joel A. Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109
USA
| | - Jennifer P. Ogilvie
- Department of Physics, University of Michigan, 450 Church St., Ann Arbor, MI 48109
USA
| |
Collapse
|