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Perego E, Zappone S, Castagnetti F, Mariani D, Vitiello E, Rupert J, Zacco E, Tartaglia GG, Bozzoni I, Slenders E, Vicidomini G. Single-photon microscopy to study biomolecular condensates. Nat Commun 2023; 14:8224. [PMID: 38086853 PMCID: PMC10716487 DOI: 10.1038/s41467-023-43969-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Biomolecular condensates serve as membrane-less compartments within cells, concentrating proteins and nucleic acids to facilitate precise spatial and temporal orchestration of various biological processes. The diversity of these processes and the substantial variability in condensate characteristics present a formidable challenge for quantifying their molecular dynamics, surpassing the capabilities of conventional microscopy. Here, we show that our single-photon microscope provides a comprehensive live-cell spectroscopy and imaging framework for investigating biomolecular condensation. Leveraging a single-photon detector array, single-photon microscopy enhances the potential of quantitative confocal microscopy by providing access to fluorescence signals at the single-photon level. Our platform incorporates photon spatiotemporal tagging, which allowed us to perform time-lapse super-resolved imaging for molecular sub-diffraction environment organization with simultaneous monitoring of molecular mobility, interactions, and nano-environment properties through fluorescence lifetime fluctuation spectroscopy. This integrated correlative study reveals the dynamics and interactions of RNA-binding proteins involved in forming stress granules, a specific type of biomolecular condensates, across a wide range of spatial and temporal scales. Our versatile framework opens up avenues for exploring a broad spectrum of biomolecular processes beyond the formation of membrane-less organelles.
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Affiliation(s)
- Eleonora Perego
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Sabrina Zappone
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Informatica, Bioingegneria, Robotica e Ingegneria dei Sistemi, University of Genoa, Genoa, Italy
| | - Francesco Castagnetti
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Davide Mariani
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Erika Vitiello
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Jakob Rupert
- RNA Systems Biology, Istituto Italiano di Tecnologia, Genoa, Italy
- Department of Biology and Biotechnologies 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Elsa Zacco
- RNA Systems Biology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Gian Gaetano Tartaglia
- RNA Systems Biology, Istituto Italiano di Tecnologia, Genoa, Italy
- Department of Biology and Biotechnologies 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Irene Bozzoni
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genoa, Italy
- Department of Biology and Biotechnologies 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Eli Slenders
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy.
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2
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Sheppard CJR, Castello M, Tortarolo G, Zunino A, Slenders E, Bianchini P, Vicidomini G, Diaspro A. Image scanning microscopy with a doughnut beam: signal strength and integrated intensity. J Opt Soc Am A Opt Image Sci Vis 2023; 40:1612-1619. [PMID: 37707118 DOI: 10.1364/josaa.495984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 07/11/2023] [Indexed: 09/15/2023]
Abstract
We discuss the effects of image scanning microscopy using doughnut beam illumination on the properties of signal strength and integrated intensity. Doughnut beam illumination can give better optical sectioning and background rejection than Airy disk illumination. The outer pixels of a detector array give a signal from defocused regions, so digital processing of these (e.g., by simple subtraction) can further improve optical sectioning and background rejection from a single in-focus scan.
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3
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Perego E, Zappone S, Slenders E, Castagnetti F, Vitiello E, Mariani D, Mecarelli LS, Bozzoni I, Vicidomini G. Comprehensive fluorescence lifetime fluctuation spectroscopy to investigate protein mobility during aggregation processes in living cells. Biophys J 2023; 122:16a-17a. [PMID: 36782797 DOI: 10.1016/j.bpj.2022.11.316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Eleonora Perego
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genova, Italy
| | - Sabrina Zappone
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genova, Italy
| | - Eli Slenders
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genova, Italy
| | - Francesco Castagnetti
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Erika Vitiello
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Davide Mariani
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Lorenzo S Mecarelli
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Irene Bozzoni
- Non coding RNAs in Physiology and Pathology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genova, Italy
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Sheppard CJR, Castello M, Tortarolo G, Zunino A, Slenders E, Bianchini P, Vicidomini G, Diaspro A. Signal strength and integrated intensity in confocal and image scanning microscopy. J Opt Soc Am A Opt Image Sci Vis 2023; 40:138-148. [PMID: 36607082 DOI: 10.1364/josaa.477240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
The properties of signal strength and integrated intensity in a scanned imaging system are reviewed. These properties are especially applied to confocal imaging systems, including image scanning microscopy. The integrated intensity, equal to the image of a uniform planar (sheet) object, rather than the peak of the point spread function, is a measure of the flux in an image. Analytic expressions are presented for the intensity in the detector plane for a uniform volume object, and for the resulting background. The variation in the integrated intensity with defocus for an offset point detector is presented. This axial fingerprint is independent of any pixel reassignment. The intensity in the detector plane is shown to contain the defocus information, and simple processing of the recorded data can improve optical sectioning and background rejection.
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Perego E, Slenders E, Zappone S, Vicidomini G. Fluorescence fluctuation spectroscopy with a cooled SPAD array detector to unravel molecular processes in living cells. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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6
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Slenders E, Perego E, Buttafava M, Tortarolo G, Conca E, Zappone S, Pierzynska-Mach A, Villa F, Petrini EM, Barberis A, Tosi A, Vicidomini G. Cooled SPAD array detector for low light-dose fluorescence laser scanning microscopy. Biophysical Reports 2021; 1:None. [PMID: 34939046 PMCID: PMC8651514 DOI: 10.1016/j.bpr.2021.100025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/14/2021] [Indexed: 11/30/2022]
Abstract
The single-photon timing and sensitivity performance and the imaging ability of asynchronous-readout single-photon avalanche diode (SPAD) array detectors have opened up enormous perspectives in fluorescence (lifetime) laser scanning microscopy (FLSM), such as super-resolution image scanning microscopy and high-information content fluorescence fluctuation spectroscopy. However, the strengths of these FLSM techniques depend on the many different characteristics of the detector, such as dark noise, photon-detection efficiency, after-pulsing probability, and optical cross talk, whose overall optimization is typically a trade-off between these characteristics. To mitigate this trade-off, we present, to our knowledge, a novel SPAD array detector with an active cooling system that substantially reduces the dark noise without significantly deteriorating any other detector characteristics. In particular, we show that lowering the temperature of the sensor to −15°C significantly improves the signal/noise ratio due to a 10-fold decrease in the dark count rate compared with room temperature. As a result, for imaging, the laser power can be decreased by more than a factor of three, which is particularly beneficial for live-cell super-resolution imaging, as demonstrated in fixed and living cells expressing green-fluorescent-protein-tagged proteins. For fluorescence fluctuation spectroscopy, together with the benefit of the reduced laser power, we show that cooling the detector is necessary to remove artifacts in the correlation function, such as spurious negative correlations observed in the hot elements of the detector, i.e., elements for which dark noise is substantially higher than the median value. Overall, this detector represents a further step toward the integration of SPAD array detectors in any FLSM system.
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Sheppard CJR, Castello M, Tortarolo G, Slenders E, Deguchi T, Koho SV, Bianchini P, Vicidomini G, Diaspro A. Pixel reassignment in image scanning microscopy with a doughnut beam: example of maximum likelihood restoration. J Opt Soc Am A Opt Image Sci Vis 2021; 38:1075-1084. [PMID: 34263763 DOI: 10.1364/josaa.426473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
In image scanning microscopy, the pinhole of a confocal microscope is replaced by a detector array. The point spread function for each detector element can be interpreted as the probability density function of the signal, the peak giving the most likely origin. This thus allows a form of maximum likelihood restoration, and compensation for aberrations, with similarities to adaptive optics. As an example of an aberration, we investigate theoretically and experimentally illumination with a vortex doughnut beam. After reassignment and summation over the detector array, the point spread function is compact, and the resolution and signal level higher than in a conventional microscope.
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Slenders E, Castello M, Buttafava M, Villa F, Tosi A, Lanzanò L, Koho SV, Vicidomini G. Confocal-based fluorescence fluctuation spectroscopy with a SPAD array detector. Light Sci Appl 2021; 10:31. [PMID: 33542179 PMCID: PMC7862647 DOI: 10.1038/s41377-021-00475-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/17/2020] [Accepted: 01/14/2021] [Indexed: 05/13/2023]
Abstract
The combination of confocal laser-scanning microscopy (CLSM) and fluorescence fluctuation spectroscopy (FFS) is a powerful tool in studying fast, sub-resolution biomolecular processes in living cells. A detector array can further enhance CLSM-based FFS techniques, as it allows the simultaneous acquisition of several samples-essentially images-of the CLSM detection volume. However, the detector arrays that have previously been proposed for this purpose require tedious data corrections and preclude the combination of FFS with single-photon techniques, such as fluorescence lifetime imaging. Here, we solve these limitations by integrating a novel single-photon-avalanche-diode (SPAD) array detector in a CLSM system. We validate this new implementation on a series of FFS analyses: spot-variation fluorescence correlation spectroscopy, pair-correlation function analysis, and image-derived mean squared displacement analysis. We predict that the unique combination of spatial and temporal information provided by our detector will make the proposed architecture the method of choice for CLSM-based FFS.
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Affiliation(s)
- Eli Slenders
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Marco Castello
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Luca Lanzanò
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy
| | - Sami Valtteri Koho
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy.
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Witters K, Plusquin M, Slenders E, Aslam I, Ameloot M, Roeffaers MBJ, Vangronsveld J, Nawrot TS, Bové H. Monitoring indoor exposure to combustion-derived particles using plants. Environ Pollut 2020; 266:115261. [PMID: 32745902 DOI: 10.1016/j.envpol.2020.115261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 05/23/2023]
Abstract
Indoor plants can be used to monitor atmospheric particulates. Here, we report the label-free detection of combustion-derived particles (CDPs) on plants as a monitoring tool for indoor pollution. First, we measured the indoor CDP deposition on Atlantic ivy leaves (Hedera hibernica) using two-photon femtosecond microscopy. Subsequently, to prove its effectiveness for using it as a monitoring tool, ivy plants were placed near five different indoor sources. CDP particle area and number were used as output metrics. CDP values ranged between a median particle area of 0.45 × 102 to 1.35 × 104 μm2, and a median particle number of 0.10 × 102 to 1.42 × 10³ particles for the indoor sources: control (greenhouse) < milling machine < indoor smokers < wood stove < gas stove < laser printer. Our findings demonstrate that Atlantic ivy, combined with label-free detection, can be effectively used in indoor atmospheric monitoring studies.
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Affiliation(s)
- Katrien Witters
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Michelle Plusquin
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Eli Slenders
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium
| | - Imran Aslam
- Centre for Surface Chemistry and Catalysis, Leuven University, Celestijnenlaan 200f-box 2461, 3001, Leuven, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium
| | - Maarten B J Roeffaers
- Centre for Surface Chemistry and Catalysis, Leuven University, Celestijnenlaan 200f-box 2461, 3001, Leuven, Belgium
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium; Department of Public Health and Primary Care, Leuven University, Herestraat 49 box 706, 3000, Leuven, Belgium
| | - Hannelore Bové
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium; Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium.
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10
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Sheppard CJR, Castello M, Tortarolo G, Slenders E, Deguchi T, Koho SV, Vicidomini G, Diaspro A. Image scanning microscopy with multiphoton excitation or Bessel beam illumination. J Opt Soc Am A Opt Image Sci Vis 2020; 37:1639-1649. [PMID: 33104611 DOI: 10.1364/josaa.402048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/02/2020] [Indexed: 06/11/2023]
Abstract
Image scanning microscopy is a technique of confocal microscopy in which the confocal pinhole is replaced by a detector array, and the image is reconstructed most straightforwardly by pixel reassignment. In the fluorescence mode, the detector array collects most of the fluorescent light, so the signal-to-noise ratio is much improved compared with confocal microscopy with a small pinhole, while the resolution is improved compared with conventional fluorescence microscopy. Here we consider two cases in which the illumination and detection point spread functions are dissimilar: illumination with a Bessel beam and multiphoton microscopy. It has been shown previously that for Bessel beam illumination in image scanning microscopy with a large array, the imaging performance is degraded. On the other hand, it is also known that the resolution of confocal microscopy is improved by Bessel beam illumination. Here we analyze image scanning microscopy with Bessel beam illumination together with a small array and show that an improvement in transverse resolution (width of the point spread function) by a factor of 1.78 compared with a conventional fluorescence microscope can be obtained. We also examine the behavior of image scanning microscopy in two- or three-photon fluorescence and for two-photon excitation also with Bessel beam illumination. The combination of the optical sectioning effect of image scanning microscopy with multiphoton microscopy reduces background from the sample surface, which can increase penetration depth. For a detector array size of two Airy units, the resolution of two-photon image scanning microscopy is a factor 1.85 better and the peak of the point spread function 2.84 times higher than in nonconfocal two-photon fluorescence. The resolution of three-photon image scanning microscopy is a factor 2.10 better, and the peak of the point spread function is 3.77 times higher than in nonconfocal three-photon fluorescence. The resolution of two-photon image scanning microscopy with Bessel beam illumination is a factor 2.13 better than in standard two-photon fluorescence. Axial resolution and optical sectioning in two-photon or three-photon fluorescence are also improved by using the image scanning modality.
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Koho SV, Slenders E, Tortarolo G, Castello M, Buttafava M, Villa F, Tcarenkova E, Ameloot M, Bianchini P, Sheppard CJR, Diaspro A, Tosi A, Vicidomini G. Two-photon image-scanning microscopy with SPAD array and blind image reconstruction. Biomed Opt Express 2020; 11:2905-2924. [PMID: 32637232 DOI: 10.1101/563288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 04/20/2020] [Accepted: 04/26/2020] [Indexed: 05/25/2023]
Abstract
Two-photon excitation (2PE) laser scanning microscopy is the imaging modality of choice when one desires to work with thick biological samples. However, its spatial resolution is poor, below confocal laser scanning microscopy. Here, we propose a straightforward implementation of 2PE image scanning microscopy (2PE-ISM) that, by leveraging our recently introduced single-photon avalanche diode (SPAD) array detector and a novel blind image reconstruction method, is shown to enhance the effective resolution, as well as the overall image quality of 2PE microscopy. With our adaptive pixel reassignment procedure ∼1.6 times resolution increase is maintained deep into thick semi-transparent samples. The integration of Fourier ring correlation based semi-blind deconvolution is shown to further enhance the effective resolution by a factor of ∼2 - and automatic background correction is shown to boost the image quality especially in noisy images. Most importantly, our 2PE-ISM implementation requires no calibration measurements or other input from the user, which is an important aspect in terms of day-to-day usability of the technique.
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Affiliation(s)
- Sami V Koho
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- University of Turku, Department of Cell Biology and Anatomy, Institute of Biomedicine and Medicity Research Laboratories, Laboratory of Biophysics, Turku, Finland
- These authors contributed equally to this work
| | - Eli Slenders
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Hasselt University, Biomedical Research Institute (BIOMED), Diepenbeek, Belgium
- These authors contributed equally to this work
| | - Giorgio Tortarolo
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Informatiche, Bioingegneria, Robotica e Ingegneria dei Sistemi, University of Genoa, Italy
| | - Marco Castello
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Elena Tcarenkova
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- University of Turku, Department of Cell Biology and Anatomy, Institute of Biomedicine and Medicity Research Laboratories, Laboratory of Biophysics, Turku, Finland
| | - Marcel Ameloot
- Hasselt University, Biomedical Research Institute (BIOMED), Diepenbeek, Belgium
| | | | | | - Alberto Diaspro
- Nanoscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Fisica, University of Genoa, Genoa, Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
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Koho SV, Slenders E, Tortarolo G, Castello M, Buttafava M, Villa F, Tcarenkova E, Ameloot M, Bianchini P, Sheppard CJR, Diaspro A, Tosi A, Vicidomini G. Two-photon image-scanning microscopy with SPAD array and blind image reconstruction. Biomed Opt Express 2020; 11:2905-2924. [PMID: 32637232 PMCID: PMC7316014 DOI: 10.1364/boe.374398] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 04/20/2020] [Accepted: 04/26/2020] [Indexed: 05/07/2023]
Abstract
Two-photon excitation (2PE) laser scanning microscopy is the imaging modality of choice when one desires to work with thick biological samples. However, its spatial resolution is poor, below confocal laser scanning microscopy. Here, we propose a straightforward implementation of 2PE image scanning microscopy (2PE-ISM) that, by leveraging our recently introduced single-photon avalanche diode (SPAD) array detector and a novel blind image reconstruction method, is shown to enhance the effective resolution, as well as the overall image quality of 2PE microscopy. With our adaptive pixel reassignment procedure ∼1.6 times resolution increase is maintained deep into thick semi-transparent samples. The integration of Fourier ring correlation based semi-blind deconvolution is shown to further enhance the effective resolution by a factor of ∼2 - and automatic background correction is shown to boost the image quality especially in noisy images. Most importantly, our 2PE-ISM implementation requires no calibration measurements or other input from the user, which is an important aspect in terms of day-to-day usability of the technique.
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Affiliation(s)
- Sami V. Koho
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- University of Turku, Department of Cell Biology and Anatomy, Institute of Biomedicine and Medicity Research Laboratories, Laboratory of Biophysics, Turku, Finland
- These authors contributed equally to this work
| | - Eli Slenders
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Hasselt University, Biomedical Research Institute (BIOMED), Diepenbeek, Belgium
- These authors contributed equally to this work
| | - Giorgio Tortarolo
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Informatiche, Bioingegneria, Robotica e Ingegneria dei Sistemi, University of Genoa, Italy
| | - Marco Castello
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Federica Villa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Elena Tcarenkova
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- University of Turku, Department of Cell Biology and Anatomy, Institute of Biomedicine and Medicity Research Laboratories, Laboratory of Biophysics, Turku, Finland
| | - Marcel Ameloot
- Hasselt University, Biomedical Research Institute (BIOMED), Diepenbeek, Belgium
| | | | | | - Alberto Diaspro
- Nanoscopy, Istituto Italiano di Tecnologia, Genoa, Italy
- Dipartimento di Fisica, University of Genoa, Genoa, Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
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Bové H, Bongaerts E, Slenders E, Bijnens EM, Saenen ND, Gyselaers W, Van Eyken P, Plusquin M, Roeffaers MBJ, Ameloot M, Nawrot TS. Ambient black carbon particles reach the fetal side of human placenta. Nat Commun 2019; 10:3866. [PMID: 31530803 PMCID: PMC6748955 DOI: 10.1038/s41467-019-11654-3] [Citation(s) in RCA: 318] [Impact Index Per Article: 63.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 06/25/2019] [Indexed: 01/02/2023] Open
Abstract
Particle transfer across the placenta has been suggested but to date, no direct evidence in real-life, human context exists. Here we report the presence of black carbon (BC) particles as part of combustion-derived particulate matter in human placentae using white-light generation under femtosecond pulsed illumination. BC is identified in all screened placentae, with an average (SD) particle count of 0.95 × 104 (0.66 × 104) and 2.09 × 104 (0.9 × 104) particles per mm3 for low and high exposed mothers, respectively. Furthermore, the placental BC load is positively associated with mothers’ residential BC exposure during pregnancy (0.63–2.42 µg per m3). Our finding that BC particles accumulate on the fetal side of the placenta suggests that ambient particulates could be transported towards the fetus and represents a potential mechanism explaining the detrimental health effects of pollution from early life onwards. Exposure to air pollution during pregnancy has been associated with impaired birth outcomes. Here, Bové et al. report evidence of black carbon particle deposition on the fetal side of human placentae, including at early stages of pregnancy, suggesting air pollution could affect birth outcome through direct effects on the fetus.
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Affiliation(s)
- Hannelore Bové
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium.,Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium.,Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F-box 2461, 3001, Leuven, Belgium
| | - Eva Bongaerts
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Eli Slenders
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium
| | - Esmée M Bijnens
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Nelly D Saenen
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Wilfried Gyselaers
- Department of Obstetrics, East-Limburg Hospital, Schiepse Bos 6, 3600, Genk, Belgium
| | - Peter Van Eyken
- Department of Obstetrics, East-Limburg Hospital, Schiepse Bos 6, 3600, Genk, Belgium
| | - Michelle Plusquin
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium
| | - Maarten B J Roeffaers
- Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F-box 2461, 3001, Leuven, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, 3590, Diepenbeek, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590, Diepenbeek, Belgium. .,Department of Public Health and Primary Care, KU Leuven, Herestraat 49-box 706, 3000, Leuven, Belgium.
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14
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Bové H, Devoght J, Rasking L, Peters M, Slenders E, Roeffaers M, Jorge-Peñas A, Van Oosterwyck H, Ameloot M. Combustion-derived particles inhibit in vitro human lung fibroblast-mediated matrix remodeling. J Nanobiotechnology 2018; 16:82. [PMID: 30368242 PMCID: PMC6204012 DOI: 10.1186/s12951-018-0410-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The continuously growing human exposure to combustion-derived particles (CDPs) drives in depth investigation of the involved complex toxicological mechanisms of those particles. The current study evaluated the hypothesis that CDPs could affect cell-induced remodeling of the extracellular matrix due to their underlying toxicological mechanisms. The effects of two ultrafine and one fine form of CDPs on human lung fibroblasts (MRC-5 cell line) were investigated, both in 2D cell culture and in 3D collagen type I hydrogels. A multi-parametric analysis was employed. RESULTS In vitro dynamic 3D analysis of collagen matrices showed that matrix displacement fields induced by human lung fibroblasts are disturbed when exposed to carbonaceous particles, resulting in inhibition of matrix remodeling. In depth analysis using general toxicological assays revealed that a plausible explanation comprises a cascade of numerous detrimental effects evoked by the carbon particles, including oxidative stress, mitochondrial damage and energy storage depletion. Also, ultrafine particles revealed stronger toxicological and inhibitory effects compared to their larger counterparts. The inhibitory effects can be almost fully restored when treating the impaired cells with antioxidants like vitamin C. CONCLUSIONS The unraveled in vitro pathway, by which ultrafine particles alter the fibroblasts' vital role of matrix remodeling, extends our knowledge about the contribution of these biologically active particles in impaired lung tissue repair mechanisms, and development and exacerbation of chronic lung diseases. The new insights may even pave the way to precautionary actions. The results provide justification for toxicological assessments to include mechanism-linked assays besides the traditional in vitro toxicological screening assays.
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Affiliation(s)
- Hannelore Bové
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, Diepenbeek, Belgium. .,Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, Louvain, Belgium.
| | - Jens Devoght
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, Diepenbeek, Belgium
| | - Leentje Rasking
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, Diepenbeek, Belgium
| | - Martijn Peters
- Institute for Materials Research, Hasselt University, Agoralaan Building D, Diepenbeek, Belgium
| | - Eli Slenders
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, Diepenbeek, Belgium
| | - Maarten Roeffaers
- Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, Louvain, Belgium
| | - Alvaro Jorge-Peñas
- Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, Box 2419, Louvain, Belgium
| | - Hans Van Oosterwyck
- Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300C, Box 2419, Louvain, Belgium.,Prometheus, div. Skeletal Tissue Engineering, KU Leuven, Louvain, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, Agoralaan Building C, Diepenbeek, Belgium
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15
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Slenders E, Bové H, Urbain M, Mugnier Y, Sonay AY, Pantazis P, Bonacina L, Vanden Berghe P, vandeVen M, Ameloot M. Image Correlation Spectroscopy with Second Harmonic Generating Nanoparticles in Suspension and in Cells. J Phys Chem Lett 2018; 9:6112-6118. [PMID: 30273489 DOI: 10.1021/acs.jpclett.8b02686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The absence of photobleaching, blinking, and saturation combined with a high contrast provides unique advantages of higher-harmonic generating nanoparticles over fluorescent probes, allowing for prolonged correlation spectroscopy studies. We apply the coherent intensity fluctuation model to study the mobility of second harmonic generating nanoparticles. A concise protocol is presented for quantifying the diffusion coefficient from a single spectroscopy measurement without the need for separate point-spread-function calibrations. The technique's applicability is illustrated on nominally 56 nm LiNbO3 nanoparticles. We perform label-free raster image correlation spectroscopy imaging in aqueous suspension and spatiotemporal image correlation spectroscopy in A549 human lung carcinoma cells. In good agreement with the expected theoretical result, the measured diffusion coefficient in water at room temperature is (7.5 ± 0.3) μm2/s. The diffusion coefficient in the cells is more than 103 times lower and heterogeneous, with an average of (3.7 ± 1.5) × 10-3 μm2/s.
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Affiliation(s)
- Eli Slenders
- Biomedical Research Institute (BIOMED) , Hasselt University , Agoralaan Bldg. C , 3590 Diepenbeek , Belgium
| | - Hannelore Bové
- Biomedical Research Institute (BIOMED) , Hasselt University , Agoralaan Bldg. C , 3590 Diepenbeek , Belgium
| | - Mathias Urbain
- Univ. Savoie Mont Blanc, SYMME , F-74000 Annecy , France
| | | | - Ali Yasin Sonay
- Department of Biosystems Science and Engineering , ETH Zürich , Mattenstrasse 26 , 4058 Basel , Switzerland
| | - Periklis Pantazis
- Department of Biosystems Science and Engineering , ETH Zürich , Mattenstrasse 26 , 4058 Basel , Switzerland
- Department of Bioengineering , Imperial College London , South Kensington Campus , London SW7 2AZ , U.K
| | - Luigi Bonacina
- Department of Applied Physics , Université de Genève , Chemin de Pinchat 22 , 1211 Geneva , Switzerland
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience (LENS), TARGID , University of Leuven , Herestraat 49 , 3000 Leuven , Belgium
| | - Martin vandeVen
- Biomedical Research Institute (BIOMED) , Hasselt University , Agoralaan Bldg. C , 3590 Diepenbeek , Belgium
| | - Marcel Ameloot
- Biomedical Research Institute (BIOMED) , Hasselt University , Agoralaan Bldg. C , 3590 Diepenbeek , Belgium
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16
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Slenders E, Seneca S, Pramanik SK, Smisdom N, Adriaensens P, vandeVen M, Ethirajan A, Ameloot M. Dynamics of the phospholipid shell of microbubbles: a fluorescence photoselection and spectral phasor approach. Chem Commun (Camb) 2018; 54:4854-4857. [DOI: 10.1039/c8cc01012a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The lipid organization of microbubbles is important in many applications.
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Affiliation(s)
- Eli Slenders
- Biomedical Research Institute (BIOMED)
- Hasselt University
- Agoralaan Bldg. C
- 3590 Diepenbeek
- Belgium
| | - Senne Seneca
- Institute for Materials Research (IMO)
- Hasselt University
- Wetenschapspark 1 and Agoralaan Bldg. D
- 3590 Diepenbeek
- Belgium
| | - Sumit Kumar Pramanik
- Institute for Materials Research (IMO)
- Hasselt University
- Wetenschapspark 1 and Agoralaan Bldg. D
- 3590 Diepenbeek
- Belgium
| | - Nick Smisdom
- Biomedical Research Institute (BIOMED)
- Hasselt University
- Agoralaan Bldg. C
- 3590 Diepenbeek
- Belgium
| | - Peter Adriaensens
- Institute for Materials Research (IMO)
- Hasselt University
- Wetenschapspark 1 and Agoralaan Bldg. D
- 3590 Diepenbeek
- Belgium
| | - Martin vandeVen
- Biomedical Research Institute (BIOMED)
- Hasselt University
- Agoralaan Bldg. C
- 3590 Diepenbeek
- Belgium
| | - Anitha Ethirajan
- Institute for Materials Research (IMO)
- Hasselt University
- Wetenschapspark 1 and Agoralaan Bldg. D
- 3590 Diepenbeek
- Belgium
| | - Marcel Ameloot
- Biomedical Research Institute (BIOMED)
- Hasselt University
- Agoralaan Bldg. C
- 3590 Diepenbeek
- Belgium
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17
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Coninx L, Thoonen A, Slenders E, Morin E, Arnauts N, Op De Beeck M, Kohler A, Ruytinx J, Colpaert JV. The SlZRT1 Gene Encodes a Plasma Membrane-Located ZIP (Zrt-, Irt-Like Protein) Transporter in the Ectomycorrhizal Fungus Suillus luteus. Front Microbiol 2017; 8:2320. [PMID: 29234311 PMCID: PMC5712335 DOI: 10.3389/fmicb.2017.02320] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/10/2017] [Indexed: 11/18/2022] Open
Abstract
Zinc (Zn) is an essential micronutrient but may become toxic when present in excess. In Zn-contaminated environments, trees can be protected from Zn toxicity by their root-associated micro-organisms, in particular ectomycorrhizal fungi. The mechanisms of cellular Zn homeostasis in ectomycorrhizal fungi and their contribution to the host tree's Zn status are however not yet fully understood. The aim of this study was to identify and characterize transporters involved in Zn uptake in the ectomycorrhizal fungus Suillus luteus, a cosmopolitan pine mycobiont. Zn uptake in fungi is known to be predominantly governed by members of the ZIP (Zrt/IrtT-like protein) family of Zn transporters. Four ZIP transporter encoding genes were identified in the S. luteus genome. By in silico and phylogenetic analysis, one of these proteins, SlZRT1, was predicted to be a plasma membrane located Zn importer. Heterologous expression in yeast confirmed the predicted function and localization of the protein. A gene expression analysis via RT-qPCR was performed in S. luteus to establish whether SlZRT1 expression is affected by external Zn concentrations. SlZRT1 transcripts accumulated almost immediately, though transiently upon growth in the absence of Zn. Exposure to elevated concentrations of Zn resulted in a significant reduction of SlZRT1 transcripts within the first hour after initiation of the exposure. Altogether, the data support a role as cellular Zn importer for SlZRT1 and indicate a key role in cellular Zn uptake of S. luteus. Further research is needed to understand the eventual contribution of SlZRT1 to the Zn status of the host plant.
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Affiliation(s)
- Laura Coninx
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Anneleen Thoonen
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Eli Slenders
- Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Emmanuelle Morin
- Institut National de la Recherche Agronomique, Laboratoire d’Excellence ARBRE, UMR 1136, Université de Lorraine Interactions Arbres/Microorganismes, Champenoux, France
| | - Natascha Arnauts
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Michiel Op De Beeck
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Annegret Kohler
- Institut National de la Recherche Agronomique, Laboratoire d’Excellence ARBRE, UMR 1136, Université de Lorraine Interactions Arbres/Microorganismes, Champenoux, France
| | - Joske Ruytinx
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Jan V. Colpaert
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
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18
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Bové H, Steuwe C, Fron E, Slenders E, D'Haen J, Fujita Y, Uji-I H, vandeVen M, Roeffaers M, Ameloot M. Biocompatible Label-Free Detection of Carbon Black Particles by Femtosecond Pulsed Laser Microscopy. Nano Lett 2016; 16:3173-8. [PMID: 27104759 DOI: 10.1021/acs.nanolett.6b00502] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Although adverse health effects of carbon black (CB) exposure are generally accepted, a direct, label-free approach for detecting CB particles in fluids and at the cellular level is still lacking. Here, we report nonincandescence related white-light (WL) generation by dry and suspended carbon black particles under illumination with femtosecond (fs) pulsed near-infrared light as a powerful tool for the detection of these carbonaceous materials. This observation is done for four different CB species with diameters ranging from 13 to 500 nm, suggesting this WL emission under fs near-infrared illumination is a general property of CB particles. As the emitted radiation spreads over the whole visible spectrum, detection is straightforward and flexible. The unique property of the described WL emission allows optical detection and unequivocal localization of CB particles in fluids and in cellular environments while simultaneously colocalizing different cellular components using various specific fluorophores as shown here using human lung fibroblasts. The experiments are performed on a typical multiphoton laser-scanning microscopy platform, widely available in research laboratories.
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Affiliation(s)
- Hannelore Bové
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590 Diepenbeek, Belgium
| | | | | | - Eli Slenders
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590 Diepenbeek, Belgium
| | - Jan D'Haen
- Institute for Material Research, Hasselt University , Wetenschapspark 1, 3950 Diepenbeek, Belgium
| | | | - Hiroshi Uji-I
- Research Institute for Electronic Science, Hokkaido University , N20W10, Kita-Ward Sapporo 001-0020, Japan
| | - Martin vandeVen
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590 Diepenbeek, Belgium
| | | | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590 Diepenbeek, Belgium
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19
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Slenders E, vandeVen M, Hooyberghs J, Ameloot M. Coherent intensity fluctuation model for autocorrelation imaging spectroscopy with higher harmonic generating point scatterers-a comprehensive theoretical study. Phys Chem Chem Phys 2015; 17:18937-43. [PMID: 26130478 DOI: 10.1039/c5cp02567b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We present a general analytical model for the intensity fluctuation autocorrelation function for second and third harmonic generating point scatterers. Expressions are derived for a stationary laser beam and for scanning beam configurations for specific correlation methodologies. We discuss free translational diffusion in both three and two dimensions. At low particle concentrations, the expressions for fluorescence are retrieved, while at high particle concentrations a rescaling of the function parameters is required for a stationary illumination beam, provided that the phase shift per unit length of the beam equals zero.
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Affiliation(s)
- Eli Slenders
- Biomed, Hasselt University, Agoralaan, Bldg C, B-3590 Diepenbeek, Belgium.
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