Electron Microscopy Services

The Zeiss Crossbeam 350 is a state-of-the-art focused ion beam scanning electron microscope (FIB-SEM) that integrates a high-resolution SEM column with a gallium ion beam. This dual-beam configuration allows for precise milling of resin-embedded biological samples while simultaneously imaging the exposed surface. By repeating this layer-by-layer process, the system generates serial images that can be reconstructed into high-resolution three-dimensional datasets. This makes the Crossbeam 350 particularly powerful for ultrastructural studies of cells, organelles, and neural circuits.

Compared to traditional transmission electron microscopy (TEM), the Crossbeam 350 offers significant advantages for volumetric imaging. While TEM provides excellent resolution, it requires manual ultrathin sectioning and alignment. In contrast, the FIB-SEM enables reduced distortion in sectioning with isotropic resolution, allowing a more accurate of the cellular architecture.

The Tremblay Lab’s Zeiss Crossbeam 350 scanning electron microscope was acquired with funding from a Canada Foundation for Innovation John R. Evans Leaders Fund grant (#39965 Laboratory of ultrastructural insights into the neurobiology of aging and cognition).

The ARTOS 3D ultramicrotome (Leica Microsystems) is an automated system that produces long ribbons of serial ultrathin sections with high consistency and minimal artifacts, enabling efficient large-volume imaging.

It provides a high-throughput method for volumetric reconstruction: ARTOS generates physical serial sections that are imaged by array tomography on the Crossbeam 350, while FIB-SEM on the same Crossbeam 350 system performs in situ milling and imaging for isotropic datasets. In a correlative workflow, resin-embedded samples are sectioned with ARTOS, mapped to identify regions of interest, and then imaged by array tomography or FIB-SEM for 3D analysis.