Abstract
Fragments of living tissues, mostly from the chick embryo heart are frozen at various rapid rates of cooling, stored at liquid nitrogen temperature, then thawed and cultured in vitro. Without any previous glycerol impregnation no survival is to be found. If the tissues are soaked before freezing in glycerol-saline solutions the viability is preserved with a maximum for 25 to 30% of glycerol. The results are discussed with regard to different theories related to cold injury.