Viability of cold-adapted L cells after freezing and storage in solid CO2

Abstract Mouse L cells adapted to low temperature by repeated exposures to 4 °C for 6–8 weeks were stored in solid CO 2 at −70 °C for 7 months simultaneously with unpretreated controls. The population of the cold-adapted subline LC2 contained more living cells after thawing than did the control L cells. The increased viability of the LC2 cells was expressed by a higher number of eosin-unstained cells immediately after thawing and by a higher increase in cell number after incubation at 36 °C. The difference between the two populations was more marked after longer storage.