title: Ultra-thin resin embedding method for scanning electron microscopy of individual cells on high and low aspect ratio 3D nanostructures.
abstract: The preparation of biological cells for either scanning or transmission electron microscopy requires a complex process of fixation, dehydration and drying. Critical point drying is commonly used for samples investigated with a scanning electron beam, whereas resin-infiltration is typically used for transmission electron microscopy. Critical point drying may cause cracks at the cellular surface and a sponge-like morphology of nondistinguishable intracellular compartments. Resin-infiltrated biological samples result in a solid block of resin, which can be further processed by mechanical sectioning, however that does not allow a top view examination of small cell-cell and cell-surface contacts. Here, we propose a method for removing resin excess on biological samples before effective polymerization. In this way the cells result to be embedded in an ultra-thin layer of epoxy resin. This novel method highlights in contrast to standard methods the imaging of individual cells not only on nanostructured planar surfaces but also on topologically challenging substrates with high aspect ratio three-dimensional features by scanning electron microscopy.
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Belu
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schnitker
authors.affiliation: Department of Medical Physics & Biomedical Engineering, University College London, Malet Place Engineering Building, London WC1E 6BT, U.K.
authors.forename: S
authors.initials: S
authors.lastname: Bertazzo
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Neumann
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Mayer
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Offenhäusser
authors.affiliation: Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Santoro
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D003890:Desiccation; D004853:Epoxy Resins / Q000302:isolation & purification; D021621:Imaging, Three-Dimensional / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D049329:Nanostructures / Q000648:ultrastructure*; D009474:Neurons / Q000648:ultrastructure; D017208:Rats, Wistar; D059010:Single-Cell Analysis / Q000379:methods*; D016610:Tissue Embedding / Q000379:methods*
chemical_list: D004853:Epoxy Resins
keywords: Cells; chemical fixation; epoxy-based resins; focused ion beam; scanning electron microscopy; ultra-structures