1
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Wallace ML, Tallarida N, Schubert WW, Lambert J. Life Detection on Icy Moons Using Flow Cytometry and Intrinsically Fluorescent Biomolecules. ASTROBIOLOGY 2024; 24:710-720. [PMID: 39023355 DOI: 10.1089/ast.2023.0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
In a previous experiment, we demonstrated the capability of flow cytometry as a potential life detection technology for icy moons using exogenous fluorescent stains (Wallace et al., 2023). In this companion experiment, we demonstrated the capability of flow cytometry to detect life using intrinsically fluorescent biomolecules in addition to exogenous stains. We used a method similar to our previous work to positively identify six classes of intrinsically fluorescent biomolecules: flavins, carotenoids, chlorophyll, tryptophan, NAD+, and NAD(P)H. We demonstrated the effectiveness of this method with six known organisms and known abiotic material and showed that the cytometer is easily able to distinguish the known organisms and the known abiotic material by using the intrinsic fluorescence of these six biomolecules. To simulate a life detection experiment on an icy moon lander, we used six natural samples with unknown biotic and abiotic content. We showed that flow cytometry can identify all six intrinsically fluorescent biomolecules and can separate the biotic material from the known abiotic material on scatter plots. The use of intrinsically fluorescent biomolecules in addition to exogenous stains will potentially cast a wider net for life detection on icy moons using flow cytometry.
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Affiliation(s)
- Matthew L Wallace
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Nicholas Tallarida
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Wayne W Schubert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - James Lambert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
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2
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Cui X, Yuan H, Chen X, Meng Q, Zhang C. Newly Designed Quasi-intrinsic Photosensitizers for Fluorescence Image-Guided Two-Photon Photodynamic Therapy with Type I/II Photoreactions. J Med Chem 2024; 67:8902-8912. [PMID: 38815214 DOI: 10.1021/acs.jmedchem.4c00191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
In this work, a set of quasi-intrinsic photosensitizers are theoretically proposed based on the 2-amino-8-(1'-β-d-2'-deoxyribofuranosyl)-imidazo[1,2-α]-1,3,5-triazin-4(8H)-one (P), which could pair with the 6-amino-5-nitro-3-(1'-β-d-2'-deoxyribofuranosyl)-2(1H)-pyridone (Z) and keep the essential structural characters of nucleic acid. It is revealed that the ring expansion and electron-donating/electron-withdrawing substitution bring enhanced two-photon absorption and bright photoluminescence of these monomers, thereby facilitating the selective excitation and tumor localization through fluorescence imaging. However, instead of undergoing radiative transition (S1 → S0), the base pairing induced fluorescence quenching and rapid intersystem crossing (S1 → Tn) are observed and characterized by the reduced singlet-triplet energy gaps and large spin-orbit coupling values. To ensure the phototherapeutic properties of the considered base pairs in long-lived T1 state, we examined the vertical electron affinity as well as vertical ionization potential for production of superoxide anions via Type I photoreaction, and their required T1 energy (0.98 eV) to generate singlet oxygen 1O2 via Type II mechanism.
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Affiliation(s)
- Xixi Cui
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Hongxiu Yuan
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Xiaolin Chen
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Qingtian Meng
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
| | - Changzhe Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, P. R. China
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3
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Houston JP, Valentino S, Bitton A. Fluorescence Lifetime Measurements and Analyses: Protocols Using Flow Cytometry and High-Throughput Microscopy. Methods Mol Biol 2024; 2779:323-351. [PMID: 38526793 DOI: 10.1007/978-1-0716-3738-8_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
This chapter focuses on applications and protocols that involve the measurement of the fluorescence lifetime as an informative cytometric parameter. The timing of fluorescence decay has been well-studied for cell counting, sorting, and imaging. Therefore, provided herein is an overview of the techniques used, how they enhance cytometry protocols, and the modern techniques used for lifetime analysis. The background and theory behind fluorescence decay kinetic measurements in cells is first discussed followed by the history of the development of time-resolved flow cytometry. These sections are followed by a review of applications that benefit from the quantitative nature of fluorescence lifetimes as a photophysical trait. Lastly, perspectives on the modern ways in which the fluorescence lifetime is scanned at high throughputs which include high-speed microscopy and machine learning are provided.
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Affiliation(s)
- Jessica P Houston
- Department of Chemical & Materials Engineering, New Mexico State University, Las Cruces, NM, USA.
| | - Samantha Valentino
- Department of Chemical & Materials Engineering, New Mexico State University, Las Cruces, NM, USA
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4
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Sambrano J, Rodriguez F, Martin J, Houston JP. Toward the Development of an On-Chip Acoustic Focusing Fluorescence Lifetime Flow Cytometer. FRONTIERS IN PHYSICS 2021; 9:647985. [PMID: 34386487 PMCID: PMC8357029 DOI: 10.3389/fphy.2021.647985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Conventional flow cytometry is a valuable quantitative tool. Flow cytometers reveal physical and biochemical information from cells at a high throughput, which is quite valuable for many biomedical, biological, and diagnostic research fields. Flow cytometers range in complexity and typically provide multiparametric data for the user at rates of up to 50,000 cells measured per second. Cytometry systems are configured such that fluorescence or scattered light signals are collected per-cell, and the integrated optical signal at a given wavelength range indicates a particular cellular feature such as phenotype or morphology. When the timing of the optical signal is measured, the cytometry system becomes "time-resolved." Time-resolved flow cytometry (TRFC) instruments can detect fluorescence decay kinetics, and such measurements are consequential for Förster Resonance Energy Transfer (FRET) studies, multiplexing, and metabolic mapping, to name a few. TRFC systems capture fluorescence lifetimes at rates of thousands of cells per-second, however the approach is challenged at this throughput by terminal cellular velocities. High flow rates limit the total number of photons integrated per-cell, reducing the reliability of the average lifetime as a cytometric parameter. In this contribution, we examine an innovative approach to address this signal-to-noise issue. The technology merges time-resolved hardware with microfluidics and acoustics. We present an "acoustofluidic" time-resolved flow cytometer so that cellular velocities can be adjusted on the fly with a standing acoustic wave (SAW). Our work shows that acoustic control can be combined with time-resolved features to appropriately balance the throughput with the optical signals necessary for lifetime data.
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Affiliation(s)
- Jesus Sambrano
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
| | - Felicia Rodriguez
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
| | - John Martin
- Tiber Plasma Diagnostics, Las Cruces, NM, United States
| | - Jessica P. Houston
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
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5
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Bitton A, Sambrano J, Valentino S, Houston JP. A Review of New High-Throughput Methods Designed for Fluorescence Lifetime Sensing From Cells and Tissues. FRONTIERS IN PHYSICS 2021; 9:648553. [PMID: 34007839 PMCID: PMC8127321 DOI: 10.3389/fphy.2021.648553] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Though much of the interest in fluorescence in the past has been on measuring spectral qualities such as wavelength and intensity, there are two other highly useful intrinsic properties of fluorescence: lifetime (or decay) and anisotropy (or polarization). Each has its own set of unique advantages, limitations, and challenges in detection when it comes to use in biological studies. This review will focus on the property of fluorescence lifetime, providing a brief background on instrumentation and theory, and examine the recent advancements and applications of measuring lifetime in the fields of high-throughput fluorescence lifetime imaging microscopy (HT-FLIM) and time-resolved flow cytometry (TRFC). In addition, the crossover of these two methods and their outlooks will be discussed.
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Affiliation(s)
- Aric Bitton
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
| | - Jesus Sambrano
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
| | - Samantha Valentino
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
| | - Jessica P. Houston
- Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, United States
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6
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Bene L, Damjanovich L. When the Complex Makes It Easy: Phasor Plotting as a Model Independent Representation of Fluorescence Decay in Flow Cytometry. Cytometry A 2020; 97:1211-1216. [PMID: 32876394 DOI: 10.1002/cyto.a.24223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/07/2020] [Accepted: 08/14/2020] [Indexed: 11/07/2022]
Affiliation(s)
- László Bene
- Department of Surgery, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Damjanovich
- Department of Surgery, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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7
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Cao R, Wallrabe H, Siller K, Periasamy A. Optimization of FLIM imaging, fitting and analysis for auto-fluorescent NAD(P)H and FAD in cells and tissues. Methods Appl Fluoresc 2020; 8:024001. [PMID: 31972557 DOI: 10.1088/2050-6120/ab6f25] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Increasingly, the auto-fluorescent coenzymes NAD(P)H and FAD are being tracked by multi-photon fluorescence lifetime microscopy (FLIM) and used as versatile markers for changes in mammalian metabolism. The cellular redox state of different cell model systems, organoids and tissue sections is investigated in a range of pathologies where the metabolism is disrupted or reprogrammed; the latter is particularly relevant in cancer biology. Yet, the actual optimized process of acquiring images by FLIM, execute a correct lifetime fitting procedure and subsequent processing and analysis can be challenging for new users. Questions remain of how to optimize FLIM experiments, whether any potential photo-bleaching affects FLIM results and whether fixed specimens can be used in experiments. We have broken down the multi-step sequence into best-practice application of FLIM for NAD(P)H and FAD imaging, with images generated by a time-correlated-single-photon-counting (TCSPC) system, fitted with Becker & Hickl software and further processed with open-source ImageJ/Fiji and Python software.
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Affiliation(s)
- Ruofan Cao
- The W.M. Keck Center for Cellular Imaging, University of Virginia, Charlottesville, VA, United States of America
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8
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Kage D, Hoffmann K, Nifontova G, Krivenkov V, Sukhanova A, Nabiev I, Resch-Genger U. Tempo-spectral multiplexing in flow cytometry with lifetime detection using QD-encoded polymer beads. Sci Rep 2020; 10:653. [PMID: 31959852 PMCID: PMC6971033 DOI: 10.1038/s41598-019-56938-2] [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] [Received: 08/19/2019] [Accepted: 12/18/2019] [Indexed: 01/09/2023] Open
Abstract
Semiconductor quantum dots (QDs) embedded into polymer microbeads are known to be very attractive emitters for spectral multiplexing and colour encoding. Their luminescence lifetimes or decay kinetics have been, however, rarely exploited as encoding parameter, although they cover time ranges which are not easily accessible with other luminophores. We demonstrate here the potential of QDs made from II/VI semiconductors with luminescence lifetimes of several 10 ns to expand the lifetime range of organic encoding luminophores in multiplexing applications using time-resolved flow cytometry (LT-FCM). For this purpose, two different types of QD-loaded beads were prepared and characterized by photoluminescence measurements on the ensemble level and by single-particle confocal laser scanning microscopy. Subsequently, these lifetime-encoded microbeads were combined with dye-encoded microparticles in systematic studies to demonstrate the potential of these QDs to increase the number of lifetime codes for lifetime multiplexing and combined multiplexing in the time and colour domain (tempo-spectral multiplexing). These studies were done with a recently developed novel luminescence lifetime flow cytometer (LT-FCM setup) operating in the time-domain, that presents an alternative to reports on phase-sensitive lifetime detection in flow cytometry.
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Affiliation(s)
- Daniel Kage
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany.,Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489, Berlin, Germany
| | - Katrin Hoffmann
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany
| | - Galina Nifontova
- Laboratory of Nano-bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation
| | - Victor Krivenkov
- Laboratory of Nano-bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation
| | - Alyona Sukhanova
- Laboratoire de Recherche en Nanosciences, LRN-EA4682, Université de Reims Champagne-Ardenne, 51100, Reims, France
| | - Igor Nabiev
- Laboratory of Nano-bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation.,Laboratoire de Recherche en Nanosciences, LRN-EA4682, Université de Reims Champagne-Ardenne, 51100, Reims, France.,Sechenov First Moscow State Medical University, 119991, Moscow, Russian Federation
| | - Ute Resch-Genger
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany.
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9
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Kage D, Hoffmann K, Wittkamp M, Ameskamp J, Göhde W, Resch-Genger U. Luminescence lifetime encoding in time-domain flow cytometry. Sci Rep 2018; 8:16715. [PMID: 30425307 PMCID: PMC6233182 DOI: 10.1038/s41598-018-35137-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/30/2018] [Indexed: 01/04/2023] Open
Abstract
Time-resolved flow cytometry represents an alternative to commonly applied spectral or intensity multiplexing in bioanalytics. At present, the vast majority of the reports on this topic focuses on phase-domain techniques and specific applications. In this report, we present a flow cytometry platform with time-resolved detection based on a compact setup and straightforward time-domain measurements utilizing lifetime-encoded beads with lifetimes in the nanosecond range. We provide general assessment of time-domain flow cytometry and discuss the concept of this platform to address achievable resolution limits, data analysis, and requirements on suitable encoding dyes. Experimental data are complemented by numerical calculations on photon count numbers and impact of noise and measurement time on the obtained lifetime values.
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Affiliation(s)
- Daniel Kage
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489, Berlin, Germany
| | - Katrin Hoffmann
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany
| | - Marc Wittkamp
- Quantum Analysis GmbH, Mendelstraße 17, D-48149, Münster, Germany
| | - Jens Ameskamp
- Quantum Analysis GmbH, Mendelstraße 17, D-48149, Münster, Germany
| | - Wolfgang Göhde
- Quantum Analysis GmbH, Mendelstraße 17, D-48149, Münster, Germany
| | - Ute Resch-Genger
- Federal Institute for Materials Research and Testing (BAM), Biophotonics Division 1.2, Richard-Willstätter-Str. 11, D-12489, Berlin, Germany.
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10
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Analysis of Flow Cytometric Fluorescence Lifetime with Time-Delay Estimation of Pulse Signals. SENSORS 2018; 18:s18020442. [PMID: 29401636 PMCID: PMC5855028 DOI: 10.3390/s18020442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 02/03/2023]
Abstract
The measurement of fluorescence lifetimes emerged in flow cytometry because it is not impacted by the non-linearity, which occurs in fluorescence intensity measurements. However, this significantly increases the cost and complexity of a traditional flow cytometer. This work reports a simple method of fluorescence lifetime measurement of a flow cytometer based on the cytometric fluorescence pulse time-delay estimation and hardware time-delay calibration. The modified chirp Z-transform (MCZT) algorithm, combined with the algorithm of fine interpolation of correlation peak (FICP), is applied to improve the temporal resolution of the cross-correlation function of the scattering and fluorescence signals, which in turn improves the time-delay estimation accuracy. The estimation accuracy is verified by Gauss fitting. Cells that were labeled simultaneously with three-color reagents are measured; the statistical results of 5000 cells are compared with reference values and are verified with the pulse width variation. The results show the potential of fluorescence lifetime measurements in the traditional flow cytometer.
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11
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Houston JP, Yang Z, Sambrano J, Li W, Nichani K, Vacca G. Overview of Fluorescence Lifetime Measurements in Flow Cytometry. Methods Mol Biol 2018; 1678:421-446. [PMID: 29071689 DOI: 10.1007/978-1-4939-7346-0_18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The focus of this chapter is time-resolved flow cytometry, which is broadly defined as the ability to measure the timing of fluorescence decay from excited fluorophores that pass through cytometers or high-throughput cell counting and cell sorting instruments. We focus on this subject for two main reasons: first, to discuss the nuances of hardware and software modifications needed for these measurements because currently, there are no widespread time-resolved cytometers nor a one-size-fits-all approach; and second, to summarize the application space for fluorescence lifetime-based cell counting/sorting owing to the recent increase in the number of investigators interested in this approach. Overall, this chapter is structured into three sections: (1) theory of fluorescence decay kinetics, (2) modern time-resolved flow cytometry systems, and (3) cell counting and sorting applications. These commentaries are followed by conclusions and discussion about new directions and opportunities for fluorescence lifetime measurements in flow cytometry.
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Affiliation(s)
- Jessica P Houston
- Department of Chemical & Materials Engineering, New Mexico State University, MSC, PO Box 30001, Las Cruces, NM, 88003, USA.
| | - Zhihua Yang
- Department of Chemical & Materials Engineering, New Mexico State University, MSC, PO Box 30001, Las Cruces, NM, 88003, USA
| | - Jesse Sambrano
- Department of Chemical & Materials Engineering, New Mexico State University, MSC, PO Box 30001, Las Cruces, NM, 88003, USA
| | - Wenyan Li
- Department of Chemical & Materials Engineering, New Mexico State University, MSC, PO Box 30001, Las Cruces, NM, 88003, USA
| | - Kapil Nichani
- Department of Chemical & Materials Engineering, New Mexico State University, MSC, PO Box 30001, Las Cruces, NM, 88003, USA
| | - Giacomo Vacca
- Kinetic River Corp., 897, Independence Avenue, Suite 4A, Mountain View, CA, 94043-2357, USA
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12
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Filby A, Houston JP. Imaging cytometry: Automated morphology and feature extraction. Cytometry A 2017; 91:851-853. [DOI: 10.1002/cyto.a.23200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Andrew Filby
- Flow Cytometry Core Facility, Faculty of Medical Sciences; Newcastle University; United Kingdom
| | - Jessica P. Houston
- Department of Chemicals and Materials Engineering; New Mexico State University; New Mexico
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13
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Zhang W, Lou X, Meng X, Zhu L. Representation Method for Spectrally Overlapping Signals in Flow Cytometry Based on Fluorescence Pulse Time-Delay Estimation. SENSORS 2016; 16:s16111978. [PMID: 27886089 PMCID: PMC5134636 DOI: 10.3390/s16111978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 02/04/2023]
Abstract
Flow cytometry is being applied more extensively because of the outstanding advantages of multicolor fluorescence analysis. However, the intensity measurement is susceptible to the nonlinearity of the detection method. Moreover, in multicolor analysis, it is impossible to discriminate between fluorophores that spectrally overlap; this influences the accuracy of the fluorescence pulse signal representation. Here, we focus on spectral overlap in two-color analysis, and assume that the fluorescence follows the single exponential decay model. We overcome these problems by analyzing the influence of the spectral overlap quantitatively, which enables us to propose a method of fluorescence pulse signal representation based on time-delay estimation (between fluorescence and scattered pulse signals). First, the time delays are estimated using a modified chirp Z-transform (MCZT) algorithm and a fine interpolation of the correlation peak (FICP) algorithm. Second, the influence of hardware is removed via calibration, in order to acquire the original fluorescence lifetimes. Finally, modulated signals containing phase shifts associated with these lifetimes are created artificially, using a digital signal processing method, and reference signals are introduced in order to eliminate the influence of spectral overlap. Time-delay estimation simulation and fluorescence signal representation experiments are conducted on fluorescently labeled cells. With taking the potentially overlap of autofluorescence as part of the observed fluorescence spectrum, rather than distinguishing the individual influence, the results show that the calculated lifetimes with spectral overlap can be rectified from 8.28 and 4.86 ns to 8.51 and 4.63 ns, respectively, using the comprehensive approach presented in this work. These values agree well with the lifetimes (8.48 and 4.67 ns) acquired for cells stained with single-color fluorochrome. Further, these results indicate that the influence of spectral overlap can be eliminated effectively. Moreover, modulation, mixing with reference signals, and low-pass filtering are performed with a digital signal processing method, thereby obviating the need for a high-speed analog device and complex circuit system. Finally, the flexibility of the comprehensive method presented in this work is significantly higher than that of existing methods.
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Affiliation(s)
- Wenchang Zhang
- School of Instrumentation Science & Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China.
- Beijing Key Laboratory for Optoelectronic Measurement Technology, Beijing Information Science & Technology University, Beijing 100101, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Beijing Information Science and Technology University, Beijing 100101, China.
| | - Xiaoping Lou
- Beijing Key Laboratory for Optoelectronic Measurement Technology, Beijing Information Science & Technology University, Beijing 100101, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Beijing Information Science and Technology University, Beijing 100101, China.
| | - Xiaochen Meng
- Beijing Key Laboratory for Optoelectronic Measurement Technology, Beijing Information Science & Technology University, Beijing 100101, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Beijing Information Science and Technology University, Beijing 100101, China.
| | - Lianqing Zhu
- Beijing Key Laboratory for Optoelectronic Measurement Technology, Beijing Information Science & Technology University, Beijing 100101, China.
- Beijing Laboratory for Biomedical Detection Technology and Instrument, Beijing Information Science and Technology University, Beijing 100101, China.
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14
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Szöllősi J, Vereb G, Nagy P. The flow of events: How the sequence of molecular interactions is seen by the latest, user-friendly high throughput flow cytometric FRET. Cytometry A 2016; 89:881-885. [DOI: 10.1002/cyto.a.22994] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/12/2016] [Accepted: 09/15/2016] [Indexed: 12/22/2022]
Affiliation(s)
- János Szöllősi
- Department of Biophysics and Cell Biology, Faculty of Medicine; University of Debrecen; Debrecen Hungary
- MTA-DE Cell Biology and Signaling Research Group, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen; Debrecen Hungary
| | - György Vereb
- Department of Biophysics and Cell Biology, Faculty of Medicine; University of Debrecen; Debrecen Hungary
| | - Péter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine; University of Debrecen; Debrecen Hungary
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15
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Houston J, Tárnok A. Perspectives of an ISAC Marylou Ingram Scholar. Cytometry A 2016; 89:627-8. [PMID: 27442839 DOI: 10.1002/cyto.a.22908] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 06/27/2016] [Indexed: 01/08/2023]
Affiliation(s)
- Jessica Houston
- Chemical & Materials Engineering, New Mexico State University, Las Cruces, New Mexico
| | - Attila Tárnok
- Saxonian Incubator for Clinical Translation (SIKT), University Leipzig, Leipzig, Germany.,Institute of Clinical Immunology, Medical Faculty, University of Leipzig, Leipzig, Germany
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16
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Cao R, Jenkins P, Peria W, Sands B, Naivar M, Brent R, Houston JP. Phasor plotting with frequency-domain flow cytometry. OPTICS EXPRESS 2016; 24:14596-607. [PMID: 27410612 PMCID: PMC5025209 DOI: 10.1364/oe.24.014596] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/14/2016] [Accepted: 06/04/2016] [Indexed: 05/23/2023]
Abstract
Interest in time resolved flow cytometry is growing. In this paper, we collect time-resolved flow cytometry data and use it to create polar plots showing distributions that are a function of measured fluorescence decay rates from individual fluorescently-labeled cells and fluorescent microspheres. Phasor, or polar, graphics are commonly used in fluorescence lifetime imaging microscopy (FLIM). In FLIM measurements, the plotted points on a phasor graph represent the phase-shift and demodulation of the frequency-domain fluorescence signal collected by the imaging system for each image pixel. Here, we take a flow cytometry cell counting system, introduce into it frequency-domain optoelectronics, and process the data so that each point on a phasor plot represents the phase shift and demodulation of an individual cell or particle. In order to demonstrate the value of this technique, we show that phasor graphs can be used to discriminate among populations of (i) fluorescent microspheres, which are labeled with one fluorophore type; (ii) Chinese hamster ovary (CHO) cells labeled with one and two different fluorophore types; and (iii) Saccharomyces cerevisiae cells that express combinations of fluorescent proteins with different fluorescence lifetimes. The resulting phasor plots reveal differences in the fluorescence lifetimes within each sample and provide a distribution from which we can infer the number of cells expressing unique single or dual fluorescence lifetimes. These methods should facilitate analysis time resolved flow cytometry data to reveal complex fluorescence decay kinetics.
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Affiliation(s)
- Ruofan Cao
- Department of Chemical and Materials Engineering, New Mexico State University, MSC 3805, PO BOX 30001, 1040 South Horseshoe Drive, Las Cruces, NM 88003,
USA
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shanxi,
China
- Bioinspired Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an, Shanxi,
China
| | - Patrick Jenkins
- Department of Chemical and Materials Engineering, New Mexico State University, MSC 3805, PO BOX 30001, 1040 South Horseshoe Drive, Las Cruces, NM 88003,
USA
| | - William Peria
- Fred Hutchinson Cancer Research Center, Seattle, WA,
USA
| | - Bryan Sands
- Fred Hutchinson Cancer Research Center, Seattle, WA,
USA
| | | | - Roger Brent
- Fred Hutchinson Cancer Research Center, Seattle, WA,
USA
| | - Jessica P. Houston
- Department of Chemical and Materials Engineering, New Mexico State University, MSC 3805, PO BOX 30001, 1040 South Horseshoe Drive, Las Cruces, NM 88003,
USA
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17
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Affiliation(s)
- Attila Tárnok
- Department of Pediatric Cardiology, Heart Centre Leipzig, Leipzig, Germany.,Institute of Clinical Immunology, Medical Faculty, University of Leipzig, Leipzig, Germany
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18
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Nedbal J, Visitkul V, Ortiz-Zapater E, Weitsman G, Chana P, Matthews DR, Ng T, Ameer-Beg SM. Time-domain microfluidic fluorescence lifetime flow cytometry for high-throughput Förster resonance energy transfer screening. Cytometry A 2015; 87:104-18. [PMID: 25523156 PMCID: PMC4440390 DOI: 10.1002/cyto.a.22616] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 11/12/2014] [Accepted: 12/03/2014] [Indexed: 01/22/2023]
Abstract
Sensing ion or ligand concentrations, physico-chemical conditions, and molecular dimerization or conformation change is possible by assays involving fluorescent lifetime imaging. The inherent low throughput of imaging impedes rigorous statistical data analysis on large cell numbers. We address this limitation by developing a fluorescence lifetime-measuring flow cytometer for fast fluorescence lifetime quantification in living or fixed cell populations. The instrument combines a time-correlated single photon counting epifluorescent microscope with microfluidics cell-handling system. The associated computer software performs burst integrated fluorescence lifetime analysis to assign fluorescence lifetime, intensity, and burst duration to each passing cell. The maximum safe throughput of the instrument reaches 3,000 particles per minute. Living cells expressing spectroscopic rulers of varying peptide lengths were distinguishable by Förster resonant energy transfer measured by donor fluorescence lifetime. An epidermal growth factor (EGF)-stimulation assay demonstrated the technique's capacity to selectively quantify EGF receptor phosphorylation in cells, which was impossible by measuring sensitized emission on a standard flow cytometer. Dual-color fluorescence lifetime detection and cell-specific chemical environment sensing were exemplified using di-4-ANEPPDHQ, a lipophilic environmentally sensitive dye that exhibits changes in its fluorescence lifetime as a function of membrane lipid order. To our knowledge, this instrument opens new applications in flow cytometry which were unavailable due to technological limitations of previously reported fluorescent lifetime flow cytometers. The presented technique is sensitive to lifetimes of most popular fluorophores in the 0.5-5 ns range including fluorescent proteins and is capable of detecting multi-exponential fluorescence lifetime decays. This instrument vastly enhances the throughput of experiments involving fluorescence lifetime measurements, thereby providing statistically significant quantitative data for analysis of large cell populations. © 2014 International Society for Advancement of Cytometry.
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Affiliation(s)
- Jakub Nedbal
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
| | - Viput Visitkul
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
| | - Elena Ortiz-Zapater
- Division of Asthma, Allergy & Lung Biology, King's College LondonUnited Kingdom
| | | | - Prabhjoat Chana
- Immune Monitoring Laboratory, NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College LondonUnited Kingdom
| | - Daniel R Matthews
- Queensland Brain Institute, The University of QueenslandSt Lucia, Australia
| | - Tony Ng
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
- UCL Cancer Institute, University College LondonUnited Kingdom
| | - Simon M Ameer-Beg
- Division of Cancer Studies, King's College LondonUnited Kingdom
- Randall Division of Cell and Molecular Biophysics, King's College LondonUnited Kingdom
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19
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Bene L, Damjanovich L. The other side of the coin: time-domain fluorescence lifetime in flow. Cytometry A 2014; 87:101-3. [PMID: 25515417 DOI: 10.1002/cyto.a.22615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 12/03/2014] [Indexed: 11/07/2022]
Affiliation(s)
- László Bene
- Department of Surgery, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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