Targeting Ultrastuctural Observation of Biological Samples by Using Capsule-Supporting Ring
Abstract: The goal of specimen preparation for transmission electron microscopy is to obtain high–quality ultra-thin sections with which we can correlate cellular structure to physiological function. In practice, prior to ultra-thin sectioning, semi-thin sections are usually examined to screen the sample quality at light microscopic level. The screened semi-thin sections are utilizable to obtain the desired ultra-thin sections after re-embedding into the same resin. Recently, we have developed a new capsule-supporting ring useful for re-embedding of semi-thin sections to be cut into ultrathin sections for electron microscopy. The capsule-supporting ring, punched out from a sheet of ethylene-vinyl acetate (EVA) resin foam, is attached with adhesive tape on one face which prevents leakage of resin and also occasional sliding of the capsule during polymerization of resin. For electron microscopy of the cultured cells, the present method enables us to culture, fix, and embed the cells in situ cultivated on a coverslip, preserving ultrastructures close to their native state. The capsule-supporting ring is also applicable to low viscous hydrophilic resins, such as Lowicryl series, useful for gold labeling. We practically describe this new preparation technique for targeting ultrastuctural observation by means of the capsule-supporting ring.
Key words: Capsule-supporting ring, resin embedding, electron microscopy, sample preparation