200kV Transmission electron microscope

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Current developments in the field of electron microscopy increasingly move in the direction of describing ultrastructural features in 3D, which drives the implementation of electron tomography. Electron tomography is one of the techniques offered by the Electron Microscopy Core Facility (EMCF) at Heidelberg University, a facility which provides technical and scientific support for transmission and scanning electron microscopy to all members of the university. We are applying for a 200kV transmission electron microscope (TEM) with a field emission gun, which is standard for good quality electron tomography, and a bottom mounted CMOS 4K camera as well as a scanning transmission electron microscope (STEM) detector. We plan to use the microscope for three purposes essential for state-of-the-art imaging of the Core Facility’s large user base. Firstly, the microscope will be the primary machine for 3D electron microscopy, that is high resolution electron tomography of sections of resin embedded material, allowing to maintain and improve this technique in the portfolio of the facility. Secondly, the STEM detector will enable us to use the more recent STEM tomography technology, addressing the demand for high-resolution, large-volume imaging of biological specimens. STEM tomography allows to increase the section thickness about threefold with high spatial resolution and is demanded by many of the EMCF users who study structures in their cellular environment. The increased section thickness when using STEM is also an advantage when targeting specific structures by correlative light and electron microscopy, a technique already offered at the EMCF with increasing user demand for targeting rare and small structures. Thirdly, the renewal of instruments is necessary since the three EMCF transmission electron microscopes for resin embedded specimens, accessible by everyone on campus, are either out of order or are coming close to their end of life. To prevent an interruption in service to the scientific community due to malfunctioning microscopes we need to ensure a timely modernization of the TEM microscopes at the facility. Thanks to the versatility of modern microscopes, allowing switching between different voltages and recalling saved alignments, the instrument will therefore not only replace the existing instrument, but also act as a backup instrument for regular thin section 2D EM.