Preserving Morphological Detail and Microarchitecture in Human Peripheral Nerves: A Comparison of Frozen, Paraffin, and Resin Histology

This study compared the morphological detail and anatomical preservation of human median and ulnar nerves following frozen, paraffin, and resin histology techniques. The median and ulnar nerves of one human cadaver arm were harvested and cut into 6 specimens each (n = 12 total). Following formalin fixation, ulnar and median nerves were processed using paraffin, frozen, and acrylic resin techniques. Samples were cut longitudinally and stained with hematoxylin and eosin (H&E). Paraffin samples exhibited axonal and collagenous tissue damage, shredding artifacts, and tissue shrinking. Frozen samples demonstrated diminished staining with artificially increased axon spacing and collagen dispersion. Resin samples demonstrated almost artifact-free tissue preservation with anatomical axon alignment and intact connective tissues. Resin provided the greatest morphological detail and tissue preservation, while frozen and paraffin techniques led to artifacts and morphological compromise that would make identification of microstructural damage challenging. We suggest the use of resin embedding for high-detail evaluation of nerve microarchitecture.