Freeze Preservation of Cultured Plant Cells

Publisher Website
Google Scholar
Abstract
A slow rate of cooling (1–2°C/min) is essential for high survival during the freezing phace. Death of cells during this phase takes place at temperatures below the freezing point of the suspending media, predominantly in the temperature range 10°C to −50°C. In the absence of cryoprotectants survival drops to zero between −30°C and −40°C. Fast thawing (water bath at 37°C giving a rate of temperature rise of 120°C/min between −50°C and −10°C) yields the highest recovery of viable cells. An interaction between cooling rate and thawing rate was demonstrated; this served to emphasize the importance of fast thawing. Under the best conditions realized in these experiments the percentage survival of cells cooled to −196°C was for carrot 70–75%, for belladonna 30–40% and for sycamore 20–25%. Storage for long periods (up to 10 months) at −196°C did not lead to any decline in percentage survival. Carrot cultures which had been stored for 10 months at −196°C showed no change in cell morphology or growth potential in culture and retained embryogenic potential.