Electron Microscopy and Crystallography

Welcome

The Electron Microscopy and Crystallography Platform is an open access facility at the CIC bioGUNE. This platform is mainly focused on structural biology for life science research. For this purpose, we use transmission electron microscopy (TEM) to determinate the sub-nanometric structure of different types of samples, and high-throughput crystallization experiments and conventional in-house data collection.
Our platform offers research institutes and companies access to two cryo-transmission electron microscopes and sample preparation instrumentation, and allows users to check their crystallization experiments on-line. The sample preparation and data collection service is provided by expert staff at the Platform.

Electron Microscopy Instrumentation

  • JEM-2200FS/CR transmission electron microscope (JEOL, Japan), equipped equipped with a K2 direct electron detector device (GATAN, UK), equipped with a 200-kV field emission gun (FEG) and an omega in-column energy filter.
  • JEM-1230 transmission electron microscope (JEOL, Japan), equipped with an UltraScan 4000 SP (4008×4008 pixels) cooled slow-scan CCD camera (GATAN, UK), and equipped with a 120-kV LaB6 thermionic gun.
  • Vitrobot MARK, automated vitrification robot (FEI, The Netherlands).
  • Leica EM GP2 single-side blotting automated plunge freezer.
  • High vacuum coating system (MED 020 BALTEC) for carbon evaporation and glow discharge.
  • Workstation for data processing and access to the institute cluster: 10 nodes, Over 600 Intel Xeon CPUs, Over 5 Tb of memory, 34 GPUs (12 Geforce RTX 3090, 16 Geforce RTX 2080 and 6 Titan X).

X-Ray Crystallography
Instrumentation

  • Automated liquid handling system (Tecan).
  • Crystallization (Mosquito) robots for high-throughput screening.
  • Image analysis platform (Crystal farm), to evaluate the performance of the screenings.
  • X-ray Generator (X8-Proteum) with two detectors.
  • CCD and Mar345 image plate for in house testing and data collection.

Electron Microscopy Service Catalogue

  1. Preparation of Biological samples for specific user requirements.
  2. TEM/Cryo-TEM data collection.
  3. Cryo-Electron Tomography.
  4. Data processing and structure determination.
  5. TEM analysis for Material Science users.
Specimen preparation techniques

Biological specimens at our laboratory are typically prepared using negative staining with heavy metal salts such as uranyl acetate producing high contrast, or by cryo-fixation techniques where the samples are embedded in vitreous ice in a frozen hydrated near native state.

Three-dimensional cryo-EM reconstruction of macromolecular assemblies

Depending on the specific question and or sample, two different cryo-EM data processing methodologies can be used to form an accurate three-dimensional (3D) representation (3D-map) of the biological object with sub-nm resolution, from a set of 2D noisy cryo-EM images. One of these methods is Single Particle Analysis and another method is Cryo-Electron Tomography (cryo-ET). On the one hand, for macromolecular assemblies (in the size range of ~5-50 nm) that have identical structure by functional necessity, powerful averaging techniques can be used to eliminate noise and obtain near atomic resolution 3D maps (example. Virus, ribosomes …). On the other hand, for cell components (in the size range of ~100-1000 nm), which possess a unique structure, (example. Mitochondrion, bacteria …), they are visualized as “individuals” by obtaining one entire projection series that is aligned and reconstructed to produce a tomogram.

Macromolecular Crystallography
Service Catalogue

  • High-throughput screening of crystallization solutions (1800 commercial conditions or customized crystallization solutions).
  • Crystallization plates stored and imaged at 21ºC in a Crystal farm.
  • Crystallization plates stored at 4ºC, 18ºC, 25ºC.
  • Personal training for data collection using the X-Ray home system.
  • Support and training in quick cryosoaking technique for in-house derivatization.
  • Individual and group training from data collection to structure determination.

Service Request

For inquiries and consultations on Electron Microscopy (Cryo-EM, Cryo-ET, Cryo-TEM) and Macromolecular Crystallography projects, please contact directly with Adriana L Rojas emicroscopyplatform@cicbiogune.es