Electron Microscopy



   Service Description

The Electron Microscopy Service offers access to transmission electron microscopy (TEM), cryo-TEM and electron tomography, high resolution scanning electron microscopy (SEM), and environmental SEM. A special emphasis has been made on high-end sample preparation techniques through cryo-immobilization. All the equipment has been configured to provide its best for biological and nanomedicine applications.

   Equipment

  • Thermo ScientificFEI Tecnai G2 20 Twin Transmission Electron Microscope
  • Thermo ScientificFEI Quanta 250 FEG Scanning Electron Microscope
  • Sample preparation equipment

    • LaB6 filament
    • Tomography software
    • Cryotransmission system
    • EDS/ EDX (Energy Dispersive Xray Spectroscopy) elemental analyzer

    • Field emission gun
    • EnvironmentalSEM
    • WetSTEM
    • EDS/ EDX (Energy Dispersive Xray Spectroscopy) elemental analyzer

    • Thermo ScientificFEI Vitrobot Mark IV, for plungefreezing of watersolution samples
    • Gatan Turbo Pumping Station, for conditioning of the cryoholder under vacuum conditions
    • GatanCryo Transfer Workstation, for transferring of grids to the cryoholder under liquid nitrogentemperature conditions
    • GatanSmartSet Model 900 Cold Stage Controller, digital controller for temperature conditioning of the cryoholder
    • Leica ultramicrotome UC7, with cryoultramicrotomy module FC7, for semithin and ultrathin sections
    • Leica HPM100, for high pressure freezing cryofixation of samples at low temperatures
    • Leica AFS2, for freeze substitution resinembedding of samples at low temperatures, with automatic reagent dispenser FSP
    • Leica SCD500, for metalthin film deposition on samples for scanning electron microscopy, and glowdischarge of filmcoated grids for transmission electron microscopy
    • Leica KMR3, glassknife maker for ultramicrotomy
    • Leica MP, mounting hotplate for plastic boats on glass knives

   Applications

  • Cellular characterization: cell structures and ultrastructures visualization and its relationship to function are the most important contributions of EM to cell biology This includes not only standard visualization of embedded and stained sections but also localization of proteins inside cells through immunolabelling with a resolution around 10 nm For this high-resolution analysis, the application of sample preparation methods that preserve the ultrastructure is essential High-pressure freezing is the cryo-immobilization technique preferred for this kind of characterization Moreover, electron tomography is uniquely suited to obtain 3D reconstructions of cells and their internal structures and, thus, improve the information provided by standard 2D analysis
  • Tissue characterization: electron microscopy has a role in the characterization of interactions between cells and with other components inside tissues Moreover, high-resolution surface characterizations of bones, teeth, skin, etc, are typically performed by SEM
  • Other biological systems: leaves, flowers, insects, and microorganisms are among the structures that can be topographically characterized using SEM For these systems, as for others with high water content, ESEM has become an important tool due to its ability for surface visualization even in a 100% humidity environment, reducing sample preparation and permitting dynamic analysis through hydration-dehydration cycles Dynamics experiments are useful in Materials Science, food industry, water-oil emulsions characterization, and pharmaceutical quality control
  • Biomaterials characterization: electron microscopy plays a double role in biomaterial characterization On one hand, it provides structural and compositional information on the materials engineered to be used inside biological systems, favoring its development On the other hand, it allows us to visualize their interactions Functionalized polymeric and metallic nanoparticles for drug delivery, dental implants, bone plates and cements, and artificial tissues are among the biomaterials that can benefit from the information provided by EM
  • Macromolecular complexes characterization: structural biology can benefit from electron microscopy to determine 3D structures of macromolecular complexes Negative staining was typically employed in the past, but it has been the development of cryo-electron microscopy in combination with single particle analysis that has made EM such a very valuable tool for 3D characterization

   Services Offered

  • Transmission electron microscopy of resin-embedded and non-embedded samples and elemental analysis using Energy Dispersive X-ray Spectroscopy (EDX/ EDS).
  • Electron Tomography of room temperature (conventional) and frozen-hydrated samples (cryo-electron tomography)
  • Scanning electron microscopy for structural studies of samples and elemental analysis using Energy Dispersive X-ray Spectroscopy (EDX or EDS).
  • Environmental scanning electron microscopy of hydrated samples and dynamic experiments.
  • Wet-scanning transmission electron microscopy of samples in thin-film water solution.
  • Resin embedding of samples at room temperature (conventional) or low temperature (freeze-substitution) for ultramicrotomy.
  • Plunge-freezing of samples in water solution (vitrification) for cryo-transmission electron microscopy.
  • Cryo-fixation of samples at high pressure (High-Pressure Freezing).
  • Ultramicrotomy of resin-embedded sections (semithin and ultrathin sections).
  • Glow-discharge of film-coated transmission electron microscopy grids.
  • Data and image processing.
  • Technical advice for users regarding the selection of protocols and procedures for experiments involving electron microscopy.


Technical staff


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Calle Severo Ochoa, 35
Parque Tecnolgico de Andaluca (PTA) Campanillas, Mlaga 29590

(+34) 951 440 260
Fax: (+34) 951 440 263