The influence of cryopreservation on the ultrastructural morphology of human thyroid cells

The purpose of this study was to investigate the effects of the freeze-thaw procedure on the ultrastructural features of human thyroid cells. Four different stages of thyroid cell preparation were compared: (1) fresh surgical tissue, serving as control, (2) cell suspension before freezing, (3) cell suspension after thawing, and (4) monolayer cell culture, obtained from cells after thawing. Electron microscopic examination of cells from each stage showed that the freeze-thaw procedure used caused only minor intracellular alterations restricted to mitochondria. Some of these organelles showed low-amplitude swelling or occasionally appeared condensed. These ultrastructural changes were not paralleled by a decrease in the vitality or sensitivity of the cryopreserved cells to stimulating agents.