Biomaterial Database

Cryoultramicrotomy of ultra-rapidly frozen specimens. 1989

R L Ornberg

Baxter Healthcare Corp., Round Lake, IL 60073.

The physical events of the cryoultramicrotomy at the level of organelles and macromolecules are not completely understood. The extent to which tissue is either cut by the edge of the knife or fractured ahead of the knife is one such event. This issue of cryofracturing versus cryosectioning during cryoultramicrotomy has been examined in quick frozen, uncryoprotected rat liver. Cryosectioned specimens were freeze-substituted and edge-on views of the sectioned surface were examined in TEM. In tissue regions showing no obvious ice crystals, fracturing was rare. Regions with less adequate freezing however had numerous fractured structures. These results indicate that high quality freezing promotes sectioning over fracturing and thus works to eliminate this serious artifact.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D008867	Microtomy	The technique of using a microtome to cut thin or ultrathin sections of tissues embedded in a supporting substance. The microtome is an instrument that hold a steel, glass or diamond knife in clamps at an angle to the blocks of prepared tissues, which it cuts in sections of equal thickness.	Thin Sectioning,Ultramicrotomy,Sectioning, Thin,Sectionings, Thin,Thin Sectionings
D005629	Frozen Sections	Thinly cut sections of frozen tissue specimens prepared with a cryostat or freezing microtome.	Frozen Section,Section, Frozen,Sections, Frozen
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus