Preservation of Living Cells at −79°C with Dimethyl Sulfoxide. ∗

Summary

A simple and reliable technique for preservation of HeLa and Fl-amnion cells at −79°C with DMSO has been developed in our laboratory. The optimum concentration of DMSO is from 5% to 10%; using this concentration we have been able to preserve HeLa and Fl-amnion cells at −79°C for as long as 15 months. Large concentrations of cells as high as 10,000,000 per ml can be stored per vial. Studies of the toxicity of DMSO on tissue culture cells demonstrated that either prolonged exposure to low concentrations or shorter exposure to high concentrations of DMSO, at 37°C or 4°C are toxic to the cells.