The Electron Microscopy and Atomic Force Microscopy Core Facility is available to investigators wishing to define ultrastructural details in their experimental systems.
The EM/AFM Core has three electron microscopes and one AFM:
- A Zeiss Sigma VP field emission scanning electron microscope equipped with multiple detectors (SE, BSE, STEM and energy-dispersive X-ray spectroscopy for elemental analysis and mapping), with enhanced correlative microscopy capabilities and with a Gatan 3View2 serial block face imaging device for serial block face-scanning electron microscopy (SBF-SEM).
- A FEI Tecnai 12 Twin transmission electron microscope equipped with a Gatan 894 Ultrascan 1000 CCD camera, Gatan cryo-stage/box, and Gatan tomography holder. In addition to traditional images, single-tilt tomography series and low-dose exposure images of specimens frozen in vitreous ice can be collected using the Tecnai 12.
- A FEI Quanta 200 with environmental SEM capabilities.
- A Bruker Multimode 8 atomic force microscope provides a means for imaging the surfaces of specimens at high resolution using physical probes. Cantilever holders are available for scanning in air and in fluid. The Multimode 8 has been upgraded with a ScanAsyst-HR high speed Peak Force Tapping Scanner that offers 20X faster survey scans and 6X faster recording scans with no loss of resolution.
All instruments are user-friendly and can be operated by individual investigators following training.
In addition to providing conventional ultra-thin resin sections, the EM/AFM Core facility provides sample preparation by high pressure freezing and freeze substitution and for SBEM. Specimens can be analyzed by immunogold (pre- and post-embedding) labeling. A fully automated vitrification device, the FEI Vitrobot Mark IV, is available for plunge-freezing of aqueous (colloidal) suspension samples for particle analysis. Other types of sample preparation include negative staining, critical point drying, and shadow replicas. The recently installed RMC-Boeckeler PT-PC Ultramicrotome provides additional options for 3D reconstruction and correlative microscopy. The A3 specimen holder for SBEM extends analysis with the Gatan 3View to individual cells and small cell populations, such as cell fractions from flow cytometry. Work stations and software are available for 3D visualization and tomographic reconstruction, segmentation, and particle analysis.