Focused Ion Beam Scanning Electron Microscope

• Subject Area: Basic Research in Biology and Medicine
• Term: Funded in 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 384169430

The advent of specialized dual beam cryo-FIBSEM technology presents a breakthrough for cryo-ET. Thinning of the biological objects before cryo-ET is usually required, because of the thickness of e.g. eukaryotic cells. The applied for cryo-FIBSEM facilitates specialized milling procedure to use the focused ion beam (FIB) for micromachining a freestanding, uniform lamella that corresponds to a thin section of the object. The integrated scanning electron microscope (SEM) is required to control and monitor the milling process. Thus, the dual beam cryo-FIBSEM is a crucial instrument of the cryo-ET workflow. An important requirement here is the safe transfer of the cryo-specimen from the cryo-FIBSEM to the 300 kV cryo-TEM for tomography and also to the cryo-light microscope (cryo-LM) for identifying regions of interest by correlative cryo-fluorescence imaging. Furthermore, the instrument allows so-called FIBSEM tomography to reconstruct larger 3D volumes albeit at lower resolution than cryo-ET.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Focused Ion Beam Scanning Electron Microscope
• Instrumentation Group: 5120 Rasterelektronenmikroskope (REM)
• Applicant Institution: Charité - Universitätsmedizin Berlin
• Leader: Professor Dr. Christian M. T. Spahn