Cryopreservation of cell suspensions of Polygonum aviculare using traditional controlled rate freezing and encapsulation/dehydration protocols, a comparison of post-thaw cell recovery

The recovery of cells from suspension cultures of Polygonum aviculare after cryopreservation by encapsulation/dehydration or controlled rate freezing procedures, has provided the first opportunity for a comparison of the rela tive effectiveness of these cryopreservation techniques using the same susp ension culture. Post-thaw cell growth and cell viability, determined by tri phenyl tetrazolium chloride (TTC) reduction, after cryopreservation by enca psulation/dehydration was significantly affected by the level of cell dehyd ration, (duration of silica gel treatment) prior to freezing. For cell samp les cryopreserved using the controlled rate procedure, mannitol preculture and the addition of mannitol to the post-thaw recovery medium significantly affected the amount of postthaw cell growth and levels of TTC reduction. U sing appropriate pre- and post-thaw treatments the % change in cell fresh w eight after the two cryopreservation procedures was comparable.