Volume scanning electron microscopy methods (vSEM) are powerful tools to study the complex ultrastructure of cells. Based on automated serial imaging of sequential resin sections (array tomography) or ablated block surface (SBEM and FIB-SEM), they uniquely capture organelle shapes and interactions to produce datasets that can lead to detailed morphological quantifications. Moreover, high resolution vSEM can be achieved on large samples, whether multicellular organisms or tissues, providing an opportunity to study cell interactions within their micro-environment. Such analysis are often performed on a subset of cells, selected for their particular phenotype or identity. Targeting the acquisition to these regions is thus valuable as it dramatically optimizes the acquisition time, sampling throughput and amount of data generated. Because direct targeting within the embedded specimen is almost impossible with a vSEM modality, correlative methods have been developed to establish the position of the volume of interest with precision.
This talk will describe the methods routinely used at EMBL to perform such targeting on various specimens ranging from mouse tissues to small model organisms. They rely on the combination of fluorescence microscopy, micro-CT or synchrotron based X-ray imaging, to establish a 3D map of the specimens to be imaged by FIB-SEM.
Dr Yannick Schwab
Team leader in Cell Biology and Biophysics Unit Head of the Electron Microscopy Core Facility EMBL
Yannick Schwab is a neuroscientist by training, graduating in 2001 at the University of Strasbourg, France. After two post-doctorates in Neurobiology (in Canada and in France), he joined in 2005 the staff of the Electron Microscopy facility at the IGBMC, Strasbourg, becoming its operational manager in 2009. During that time, he developed methods in Correlative Light and Electron Microscopy (CLEM) applied to cultured cells and to model organisms.
Yannick joined EMBL in 2012, as a team leader in the Cell Biology and Biophysics Unit and as head of the Electron Microscopy Core Facility (EMCF). The Schwab team is focused on methods development in volume CLEM, combining in particular fluorescence imaging of whole-mount specimens with volume EM. The EMCF offers access to a large portfolio of techniques in cellular EM, including ultrastructural analysis, 3D electron microscopy and CLEM on a variety of biological model systems.