Correlative light-electron microscopy (CLEM) is a developing technique for combined analysis of immunostaining for various biological molecules coupled with investigations of ultrastructural features of individual cells within a large field of view. This study first introduces a method of CLEM imaging of the same endocrine cells of compact and diffuse Langerhans islets from human pancreatic tissue specimens. The method utilises serial sections obtained from Epon-embedded specimens fixed with glutaraldehyde and osmium tetroxide. Next, serial block-face imaging using scanning electron microscopy (SBF-SEM) is advanced to enable rapid and efficient acquisition of three-dimensional (3D) ultrastructural information from Langerhans islets of mouse pancreas corresponding to the CLEM images. Samples for SBF-SEM observations were postfixed with osmium and stained en bloc and embedded in conductive resins with ketjenblack significantly reduced the charging of samples during SBF-SEM imaging.
Part of the book: Electron Microscopy