Frozensection

Frozensection is a laboratory technique used to rapidly prepare thin slices of frozen specimens for microscopic analysis. It is closely related to the frozen section method used in pathology; in some contexts, frozensection is simply an alternate spelling or a composite term for this approach.

The procedure typically involves snap-freezing the tissue in a cryogenic medium such as isopentane cooled by liquid nitrogen, embedding in a freezing medium (often OCT), and mounting on a cryostat microtome. The instrument cuts sections typically 5 to 20 micrometers thick, which are mounted on glass slides, fixed briefly, and stained for rapid evaluation, often with hematoxylin and eosin or quick cytological stains. The entire process is performed inside a refrigerated unit called a cryostat to preserve tissue morphology during sectioning.

Applications include intraoperative diagnosis to guide surgical decisions, margin assessment of tumors, and rapid preliminary evaluation in various specialties such as neuropathology and gastrointestinal pathology. It is also used in some research and quality-control settings for quick morphological assessment of specimens.

Limitations include reduced cellular detail compared with paraffin-embedded sections, potential freezing artifacts such as ice crystal damage and tissue distortion, and a limited range of reliable stains. Not all tissues yield definitive results, and the accuracy depends on the experience of the pathologist or technician performing the procedure.

See also: frozen section, cryostat, intraoperative pathology, rapid diagnostics.