cryosectioning

Cryosectioning is a laboratory technique used to prepare thin tissue sections from frozen specimens for microscopic examination. It is performed in a cryostat, a refrigerated microtome housed in a dedicated chamber or benchtop instrument. After collection, tissue is rapidly frozen to preserve structural and biochemical features, using media such as optimal cutting temperature (OCT) compound or fast freezing in cooled isopentane and liquid nitrogen.

The frozen block is mounted on a chuck and cooled further inside the cryostat. The block face is trimmed to expose the tissue surface, and thin sections, typically 5–15 micrometers, are cut with a sharp blade and collected on glass slides. Sections may be fixed briefly with cold acetone or other reagents and stained immediately or used for immunohistochemistry, immunofluorescence, or rapid histochemical assays. Cryosections preserve many lipids, enzymes, and certain antigens better than paraffin-embedded sections, enabling faster diagnostic or research workflows such as intraoperative frozen sections and RNA or protein analyses.

Common artifacts include ice crystal damage, folding, or compression, which can affect morphology. These are mitigated by rapid freezing, correct embedding medium, and appropriate sectioning temperature. Limitations include somewhat lower morphological detail compared with paraffin sections and challenges with long-term storage. Overall, cryosectioning provides rapid, versatile tissue sections suitable for diagnostic, research, and intraoperative applications.