tunnsnittning

Tunnsnittning, literally thin-sectioning, is the laboratory process of producing very thin slices of a specimen for microscopic examination. The technique is used across fields such as histology, pathology, geology, and materials science to reveal internal structure, composition, and microtexture.

In histology and pathology, thin sections are prepared by fixation, dehydration, clearing, and embedding in paraffin or resin. A microtome then cuts sections typically 3–5 micrometers thick for paraffin-embedded tissue, or thinner for resin-embedded material. The sections are mounted on glass slides, stained (often with hematoxylin and eosin), and examined under light microscopy. Frozen tissue can be sectioned with a cryostat for rapid analysis, though artifacts may differ. For electron microscopy, ultrathin sections of about 60–100 nanometers are produced with an ultramicrotome and a diamond knife.

In geology and petrography, rock thin sections are usually about 30 micrometers thick. A rock sample is cut, mounted on a glass slide, and ground and polished to the target thickness. They are examined under transmitted light microscopy to identify minerals and textures.

Equipment and workflow: essential tools include microtomes or ultramicrotomes, suitable knives (steel or diamond), embedding media, and polishing equipment. The process emphasizes preserving microstructure and minimizing artifacts such as folds, chatter, or staining irregularities.

Applications and quality: thin sections support diagnostic histopathology, research, mineralogical analysis, and materials failure investigations. Quality control involves verifying thickness uniformity, absence of artifacts, and proper staining or imaging readiness, while safety considerations address chemical hazards from fixatives, solvents, and embedding resins.