Freeze-thaw-induced latent injury as a phenomenon in cryobiology

Abstract

Summary The concept of freeze-thaw-induced latent injury, or deleterious effects of freezing and thawing manifested with time after thawing, was established as a cryobiological phenomenon. Lettre ascites tumor cells were frozen slowly and thawed rapidly at rates favoring survival of sufficient cells for adequate measurements. Following 0-, 4-, and 8-hr storage periods at 22°C, split samples of unfrozen and frozen-thawed cells were evaluated in terms of respiration (Qo 2 ), reproduction, and plasma membrane integrity. Data showed that freezing and thawing greatly accelerated (15% to 62%) the loss in physiological function during storage when compared with unfrozen populations, especially in terms of respiration and reproduction. Evidence for such latent injury was demonstrated to a lesser extent by the cosin permeability test, which showed some variations between runs. Differences in percentage survival or loss among criteria employed were discussed in stressing the complexity of survival evaluation. The significance of latent injury was presented and the need for evaluation with other cells was suggested, not only in cryobiology but also in pathology of cell injury in general.