Some practical aspects of storing mammalian cells in the dry-ice chest.

Abstract

Summary A variety of cultured mammalian cells, including both permanent strains (3–16 years in vitro ) and newly isolated lines (one to five passages in vitro ) derived from several species and with diverse histories have been stored successfully at -70°C. (dry-ice chest) for periods of at least 3 years. The conditions for storage were found to be dependent on the method of freezing and thawing and on the concentration of glycerol in the medium over the range of 5–20 per cent. Conditions for optimal survival were observed to vary not only among strains from different sources, but also among nutritional variants and the stock cultures from which these were isolated. Cells deteriorated at -70°C. at a rate which was a function of the conditions of storage and the strain of cells. Under conditions for optimal survival, one group of cell strains had a half-life at -70° C. of about 3 years, whereas a second group had a half-life of 1–1.5 years.