I2BC / Plateforme de cryo-microscopie électronique (Cryo-EM)

Cryo-EM has two 200 kV and 120 kV electron cryo-microscopes (Tecnai FEI), equipped with a direct detection camera (K2 Gatan) and a cooled object holder (Gatan 626). The platform's equipment allows the observation of biological objects (proteins, multi-protein complexes, viruses, liposomes, multi-molecular assemblies, etc.) after negative staining, or by cryo-electron microscopy in their natural aqueous environment. Negative staining is used to check the quality and homogeneity of the samples, but also to get an idea of the shape of the objects and possibly to determine the stoichiometry of certain assemblies. The images obtained by cryo-electron microscopy on the FEI Tecnai G20, as well as the computing resources available on the platform, allow the determination of medium-resolution 3D structures (8 Å). These first structures are necessary to access more powerful microscopes (e.g. 300 kV Titan Krios at ESRF, Grenoble or IGBMC, Grenoble), leading to atomic resolutions. The platform also allows the observation of in situ complexes (proteins on the surface of purified organelles or enveloped viruses, membrane proteins reconstituted in liposomes, ...) by cryo-electron tomography.
This platform is part of the I2BC's Structural Biology platforms, which include: i) the Crystallization, NMR, CryoEM, Macromolecular Interaction Measurements platforms, and ii) the technical platforms for Soluble or Membrane Protein Expression in Yeast, Protein Expression in Insect Cells and Structural Bioinformatics.

• Mrs Ana Andreea ARTENI