Cryo-Plasma Focused Ion Beam Scanning Electron Microscope (Cryo-pFIB-SEM)

• Subject Area: Basic Research in Biology and Medicine
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566501987

Next generation structural cell biology: Cryo-Plasma Focused Ion Beam Scanning Electron Microscope for cryo-lamellae generation suitable for electron cryo-tomography In this application, we apply for funding of a Cryo-Plasma Focused Ion Beam Scanning Electron Microscope (pFIB-SEM) equipped with a dedicated cryo-transfer system, an integrated fluorescence microscope, and a cryo-lift out system for generating vitreous lamellae suitable for cryo-ET. The automated and streamlined production of thin and vitreous lamellae has become an essential prerequisite for acquiring high-quality tomograms from cellular/tissue specimen. This new sample preparation technique is driving a transformative impact in structural cell biology. A critical challenge in sample preparation is the targeted, high-quality, automated, and fast production of thin and vitreous lamellae from biological material so that cryo-ET can deliver high-resolution data for subsequent image analysis. Due to the thickness limitations of transmission electron microscopy that allows for imaging of samples of up to 500nm in thickness, thinning the sample is the sole way of determining the structure of macromolecular complexes in their natural environment, enabling detailed structural analyses of tissues, cells and whole microbes. pFIB-SEM systems address sample thinning with exceptional precision, and throughput. In combination with high-end cryo- transmission electron microscopes (cryo-TEM), such as those we operate at the Frankfurt Center for Electron Microscopy (FCEM) of the Goethe University Frankfurt (GU) will allows us to record state-of-the art images from samples of importance for biological and medical applications. Therefore, the structural cell biology community at GU strongly supports this initiative. Accessing pFIB-SEM systems at neighboring and collaborating institutions has not been possible due to the large number of groups (6) utilizing the sole equipment there and consequently the extremely limited measurement time. In fact, pFIB-SEM systems are the major bottleneck in the analysis for the whole community as the lamella preparation takes significantly more time compared to the tomogram acquisition. Acquiring a pFIB-SEM will enable state-of-the-art structural cell biology research at GU for the next decade.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Cryo-Plasma-Fokussiertes Ionenstrahl-Rasterelektronenmikroskop (Cryo-pFIB-SEM)
• Instrumentation Group: 5120 Rasterelektronenmikroskope (REM)
• Applicant Institution: Goethe-Universität Frankfurt am Main
• Leader: Professor Dr. Achilleas Frangakis