2D or 3D electron microscopy morphometric analysis of the central nervous system with Deep FIB-SEM and IA-based image analysis
Full workflow support on surface morphology and ultrastructural analysis in SEM and TEM
The facility is equiped with a FIB-SEM (Focused Ion Beam-Scanning Electron Microscopy), that allows volumic acquisition of resin embedded samples at nanometric resolution (up to 5nm in 3D). This technology allows observation in 3D of whole cells, small organisms and tissus. FIB-SEM can be combined to light microscopy to link functional characterization, thanks to light microscopy, to structure with electron microscopy data. The Imagerie-Gif facility proposed to combine high resolution light microscopy to volumic electron microscopy by combinin a SIM (Structured Illumination Microscopy) and a FIB-SEM.
The development occurring in the platform MEC is tighly associated with joint effort with the “platform of nanocaractérisation” (PFNC) from CEA, leading to have a unique expertise in 3D electron microscopy of large tissue volumes reaching tens of thousands of cubic micrometers at the nanometer scale. This is essential to analyze rare events and true 3D morphological details in neurobiology to study finely cell connectivity, the characterization of membrane structures in chloroplasts from algae and plants, or to study nanoparticles toxicity. Indeed, EM stacks are acquired with much less efforts than by serial sectioning and in a relatively short time (preparation of the sample 3 days, acquisition of the stack 1 day due to high quality stabilization of the samples) new biological questions of interest to the FBI community can be addressed.
Moreover, we have developed a unique pipe-line of analysis of large stacks of 3D EM images. This pipe-line is composed of segmentation steps followed by Ilastik approach for recognition of objects of interests coupled with a serie of home-made plugin specific for quantification. As requested by the network of French electronic microscopists, we are actively collaborating to make available our process to make this pipe-line available for others colleagues and especially the FBI users, as requested by the network of French electronic microscopists. Our work allowed us to develop international collaboration with Andrea Volterra, a world-class leader in the field of FIB-SEM in Neurobiology.
Member of C2RT (Center for Resources and Research in Technology) the Unit for service and technology in ultra-structural bio-imaging (UBI) at Pasteur provides technical and scientific support in electron microscopy, mainly, but not exclusively, to the Pasteur community, analyzing host-pathogen interactions at the ultra-structural level. Our equipment enables us to do state-of-the-art EM for life sciences that includes three dimensional EM by tomography and focused ion beam SEM. The ultrapole is run by ten members (eight engineers and two technicians), each specialized in certain techniques. We put a big emphasis on correlate light- and electron microscopy to study key (rare events) of host-pathogen interactions and we have designed several protocols to combine room temperature LM and cryo-LM with FIB-SEM, cryo-SEM and cryo-tomography.
The UBI also has a small research group focusing on large DNA-viruses. Through this research theme we wish to establish and develop robust, new protocols for various EM-techniques.
The cell biology pole Imagerie-Gif is localized on the CNRS campus of Gif sur Yvette, in a new building dedicated to platform activity. This IBiSA platform provides efficient access to high quality services and state of the art technologies. It is open to the whole academic scientific community and to industrial partners. The management and development of this pole is under the responsibility of the team “Dynamics of cell compartmentation” (group leader S. Lecart, Institut des Sciences du Végétal, Gif sur Yvette). It uses cell biology approaches and multiscale imaging (cytometry, bio-imaging and electron microscopy) to explore the cell. The development of new protocols and the mastering of update imaging approaches are part of the R & D objectives of the platform. Those are then transferred to platform services and disseminated through numerous training and teaching events, and opened to the whole scientific community. The cell biology pole of Imagerie-Gif activities contributes to the working groups “super resolution”, “Probe development” and “CLEM” within the France-BioImaging consortium.