Présentation des intervenants de cette conférence MEMO-22 dans l'ordre du programme.
Dr. Tatiana Novikova
LPICM, Ecole polytechnique, CNRS, Palaiseau 91128, France
Muller Polarimetry of tisssues
09:00 UTC +2 (1h):
Dr. Sandro Heuke
Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
Coherent Raman Imaging
10:30 UTC+2 (30min)
Within my talk, I will give an introduction to coherent Raman imaging (CRI), its experimental implementation and the 3 most promising innovations that are about to become standard techniques in biomedical labs arounds the world. These innovations are: (1) Stimulated Raman histology (SRH). SRH allows for the live generation of virtual hematoxylin & eosin (HE) images from freshly excised native tissue blocks facilitating the guidance of cancer surgery. (2) Bioorthogonal imaging. CRI enables for the detection of the smallest possible label introduced into a cell – a single atom – or, more precise, an isotope that cannot be found in high dosage within native cells. Application example: feeding bacteria with deuterated sugars enables to evaluate their anti-biotic resistance within 30 min. (3) Multi-stain CRI. Tagging cellular structures with more than 2 fluorophores is challenging due the increasing spectral overlap of the excitation and emission spectra. CRI chromophores containing triple bonds can be designed, however, to enable for a crosstalk free detection of up to 20 distinct cellular structures.
Dr. Valentin Dunsing
IBDM, Aix Marseille Univ, CNRS, Marseille, France
Fluorescence fluctuation spectroscopy: Quantifying molecular interactions and dynamics in complex biological systems
11:00 UTC+2 (30 min)
Living cells rely on transport and interaction of biomolecules to perform their diverse functions. To obtain a detailed understanding of these highly dynamic processes in the native environment, minimally invasive techniques are needed. A powerful toolbox of such techniques is provided by fluorescence fluctuation spectroscopy (FFS). In more detail, FFS takes advantage of the inherent dynamics present in biological systems, such as diffusion, to infer molecular parameters from fluctuations of the signal emitted by an ensemble of fluorescently tagged molecules. In my talk, I will introduce the conceptual principle of FFS and several FFS variants, such as fluorescence cross-correlation spectroscopy (FCCS). I will then present our recent efforts on 1) how to accurately quantify the stoichiometry of protein complexes in living cells by taking dark states of fluorescent probes into account, 2) how to multiplex FFS measurements using spectral detection to probe higher order molecular interactions, 3) applying FFS in biological context, e.g. studying the assembly process of Influenza viruses at the plasma membrane of cells and characterizing novel in vivo tools for chemical control of protein interactions.
Dr. Corinne Lorenzo
RESTORE, UMR 5070-CNRS 1301-INSERM EFS Univ. P. Sabatier
Introduction to Light Sheet imaging and biological application of organoid/tissue imaging
11:30 UTC+2 (30 min)
The developments of non-intrusive 3D-imaging techniques, either based on optical tomography [1] or on light sheet optical sectioning, have been strongly driven by the critical need of life scientists to observe, image and analyse biological samples, which are intrinsically three-dimensional. Despite that the seed paper introducing Light Sheet Fluorescence Microscopy (hereafter: LSFM), successfully applied to the 3D imaging of living organisms, is now out for almost a decade, the interest of life scientists in LSFM has recently started to waken, and pioneering applications sprout up. LSFM has been promoted as such an extremely powerful technique for three-dimensional studies of living and clearing specimens, with pioneering applications in cell biology [2], developmental biology (e.g. cell lineage tracing in Zebrafish [3,4] heart development [5]), marine biology [6] or plant biology [7]. Moreover, the universality and versatility of the technique has fostered cutting edge advances in other technological or application fields: real- time control systems, 3D volume rendering and manipulation, signal processing, registration and image fusion algorithms, biological systems modelling, data storage and management. LSFM, to the same extent as laser scanning confocal microscopy, now refers to a whole family of microscope systems which has evolved from the original single-cylindrical-lens microscope [8,9] to split up into many categories that differ in optical design, and are often tuned for a specific type of specimen (e.g. organ, embryo, cells, single cell, molecular dynamics) and application. Currently, LSFM represents a new strategic resource for biomedical and pharmacological innovation. Indeed, LSFM opens new perspectives for the study of mechanisms across cells within organoids and ex vivo adult mammal tissues and should enable the identification of new cellular actors responsible for the coordination of signals in an integrated physiological and/or pathological context. We will intend to provide an overview of most recent works and theirs applications in imaging tissue mimics using LSFM. A discussion of the practical conclusions with particular emphasis to applicability and bottlenecks will be given.
1 Sharpe J, et al. (2002) Optical projection tomography as a tool for 3D microscopy and gene expression studies. Science. 296(5567): 541-5.
2 Lorenzo C, et al. (2011) Live cell division dynamics monitoring in 3D large spheroid tumor models using light sheet microscopy. Cell Div. 6: 22.
3 Keller PJ, Stelzer EH (2008). Quantitative in vivo imaging of entire embryos with Digital Scanned Laser Light Sheet Fluorescence Microscopy. Curr Opin Neurobiol. 18(6): 624-32.
4 Swoger Jet al. (2011) 4D retrospective lineage tracing using SPIM for zebrafish organogenesis studies. J Biophotonics. 4(1-2): 122-34.
5 Scherz PJ, et al. (2008) High-speed imaging of developing heart valves reveals interplay of morphogenesis and function. Development. 135(6):1179-87.
6 Wu J, Li J, Chan RK. (2013) A light sheet based high throughput 3D-imaging flow cytometer for phytoplankton analysis. Opt Express. 21(12): 14474-80.7 Maizel A, et al. (2011) High-resolution live imaging of plant growth in near physiological bright conditions using light sheet fluorescence microscopy. Plant J. 68(2): 377-85.
8 Huisken J, et al. (2004). Optical sectioning deep inside live embryos by selective plane illumination microscopy. Science. 305(5686): 1007-9.
9 Voie AH, Burns DH, Spelman FA. (1993) Orthogonal-plane fluorescence optical sectioning: three-dimensional imaging of macroscopic biological specimens. J Microsc. 170(Pt 3): 229-36.
Dr. Anna F. Rigato
Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
Characterization of epithelial morphogenesis. From imaging to simulation
12:00 UTC+2 (30 min)
Morphogenesis is the complex process through which an organism develops its final shape. While some changes are rapid, some others occur during several hours. For example, epidermal morphogenesis in Drosophila takes few days and involves dramatic changes of cell shape. To study such phenomenon, we combined genetic approaches and confocal microscopy in living organisms to acquire information not only on the biological regulation the larval epidermis, but also on the physical forces that drive cell morphology. With such information, we developed a quantitative model of epidermal morphogenesis and were able to reproduce the observed cell morphologies by computer simulations.
Dr. Pascal Berto
Institut de la vision, Sorbonne Université, INSERM, CNRS, 17 rue Moreau, 75012, Paris, France
Measuring and shaping the phase of light: key applications in biology
14:00 UTC+2 (1h)
In recent decades, the advent of spatially-resolved techniques to control and image the phase of light waves has deeply transformed microscopy. In this talk, I will first demystify the notions of optical phase or wavefront, and present several important examples of phase shaping in microscopy (Light-sheet, STED,..), with a focus on the use of holograms for neurons stimulation (optogenetics) and temperature control at the microscale [2]. After discussing some limits of the standard phase shaping techniques, I will introduce a novel concept where the transmitted light is shaped using thermo-optics [1]. I will explain how this simple concept can provide arrays of electrically tuneable lenses, but also complement the existing optical shaping toolbox by offering low-chromatic-aberration, polarization-insensitive micro-components. We will finally discuss the potential of this technique for multiplane Ca2+ or Voltage Imaging.
The second part of this talk will be dedicated to phase imaging, and particularly Quantitative Phase Imaging (QPI). Phase-contrast microscopies are well known for their ability to reveal rich images related to refractive index inhomogeneities, and thus improve contrast in cells, which are essentially transparent and barely visible in brightfield microscopy. I will describe the recent research field of Quantitative Phase Imaging, which has proposed valuable label-free biomedical methods to measure biophysical cell parameters, including its dry mass. In particular, I will describe how a broadband and cost-effective quantitative phase camera can be simply implemented by placing a thin diffuser in front of a standard camera [3]. I will discuss the potential of the technique for quantitative phase imaging of biological samples and for 3D nanoparticles super-localization and tracking.
1. Berto, P., Philippet, L., Osmond, J., Liu, C. F., Afridi, A., Montagut Marques, M., Molero Agudo, B., Tessier, G. & Quidant, R. Tunable and free-form planar optics. Nature Photonics 13, 649–656 (2019).
2. Liu, C., Tessier, G., Flores Esparza, S. I., Guillon, M. & Berto, P. Reconfigurable Temperature Control at the Microscale by Light Shaping. ACS Photonics 6, (2019).
3. Berto, P., Rigneault, H. & Guillon, M. Wavefront sensing with a thin diffuser. Opt. Lett. 42, 5117 (2017).
Dr. Thomas Chaigne
Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France
Photoacoustic imaging: towards functional, single-cell resolution imaging a couple millimeters deep
15:30 UTC+2 (30 min)
Combining optical excitation and ultrasonic detection, photoacoustic imaging has emerged in the last decades as a very powerful technique to provide high resolution images of optically contrasted objects embedded deep inside biological tissue.
After presenting the basic principles of this modality, I will present a few applications with a bias toward neurobiology. I will discuss the technological key points that remain to be addressed regarding the ultrasound detection systems and molecular probes, and will present the last techniques that we developed in our group to approach single-cell resolution.
Dr. Barbara Buades
Meetoptics
16:00 UTC+2 (30 min)
Frustrated from not finding a trusted supplier within weeks for a simple achromat lens, Dr. Barbara Buades together with Dr. James Douglas decided to start MEETOPTICS: a specialised search for Optics and Photonics products where researchers and engineers can compare available products and capabilities from trusted companies in the industry.
