Development of a method of preserving suspension cultures of plant cells has been undertaken. When grown in a conventional medium containing 20 g/1 of sucrose, Daucus carota cells survived freezing and a short period of storage at −40 °C or −196 °C in the presence of a suitable protective agent, whereas Ipomoea sp. cells did not. Ipomoea cells survived freezing if they were adapted to growth in a medium containing 65 g/1 of sucrose.