Three-dimensional information is much easier to understand than a set of two-dimensional images. Therefore a layman is thrilled by the pseudo-3D image taken in a scanning electron microscope (SEM) while, when seeing a transmission electron micrograph, his imagination is challenged. First approaches to gain insight in the third dimension were to make serial microtome sections of a region of interest (ROI) and then building a model of the object. Serial microtome sectioning is a tedious and skill-demanding work and therefore seldom done. In the last two decades with the increase of computer power, sophisticated display options, and the development of new instruments, an SEM with a built-in microtome as well as a focused ion beam scanning electron microscope (FIB-SEM), serial sectioning, and 3D analysis has become far easier and faster.Due to the relief like topology of the microtome trimmed block face of resin-embedded tissue, the ROI can be searched in the secondary electron mode, and at the selected spot, the ROI is prepared with the ion beam for 3D analysis. For FIB-SEM tomography, a thin slice is removed with the ion beam and the newly exposed face is imaged with the electron beam, usually by recording the backscattered electrons. The process, also called "slice and view," is repeated until the desired volume is imaged.As FIB-SEM allows 3D imaging of biological fine structure at high resolution of only small volumes, it is crucial to perform slice and view at carefully selected spots. Finding the region of interest is therefore a prerequisite for meaningful imaging. Thin layer plastification of biofilms offers direct access to the original sample surface and allows the selection of an ROI for site-specific FIB-SEM tomography just by its pronounced topographic features.
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http://dx.doi.org/10.1007/978-1-62703-776-1_24 | DOI Listing |
Methods Mol Biol
January 2025
Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, Cambridge, UK.
Electron tomography can provide additional morphological information not easily obtained by conventional transmission electron microscopy of thin sections. It uses a goniometer stage in the electron microscope to tilt the specimen and collect a series of 2D images from different orientations, which are combined to provide a 3D volume tomogram and a colored reconstruction of the morphological feature(s) of interest. Here we describe the protocols for its use in visualizing changes in organelle morphology after depletion of the SNARE proteins VAMP7 and VAMP8 and to study VAMP7 localization on endolysosomes/lysosomes.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institute of Inorganic Chemistry (IAC), Karlsruhe Institute of Technology (KIT) Engesserstraße 15 D-76131 Karlsruhe Germany
Pt-CeO nanosponges (1 wt% Pt) with high surface area (113 m g), high pore volume (0.08 cm g) and small-sized Pt nanoparticles (1.8 ± 0.
View Article and Find Full Text PDFISME J
January 2025
Université Aix-Marseille, CNRS, CEA, UMR7265 Institut de Biosciences and Biotechnologies d'Aix-Marseille, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France.
Intracellular calcium carbonate formation has long been associated with a single genus of giant Gammaproteobacteria, Achromatium. However, this biomineralization has recently received increasing attention after being observed in photosynthetic Cyanobacteriota and in two families of magnetotactic bacteria affiliated with the Alphaproteobacteria. In the latter group, bacteria form not only intracellular amorphous calcium carbonates into large inclusions that are refringent under the light microscope, but also intracellular ferrimagnetic crystals into organelles called magnetosomes.
View Article and Find Full Text PDFSubcell Biochem
December 2024
Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
Understanding the dynamic processes involving virus structural components within host cells is crucial for comprehending viral infection, as viruses rely entirely on host cells for replication. Viral infection involves various intracellular stages, including cell entry, genome uncoating, replication, transcription and translation, assembly of new virus particles in a complex morphogenetic process, and the release of new virions from the host cell. These events are dynamic and scarce and can be obscured by other cellular processes, necessitating novel approaches for their in situ characterization.
View Article and Find Full Text PDFMol Autism
December 2024
Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Background: Angelman syndrome (AS), a severe neurodevelopmental disorder resulting from the loss of the maternal UBE3A gene, is marked by changes in the brain's white matter (WM). The extent of WM abnormalities seems to correlate with the severity of clinical symptoms, but these deficits are still poorly characterized or understood. This study provides the first large-scale measurement of WM volume reduction in children with AS.
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