Table 2.
Thawing method | Time taken to thaw (min) | Viability (%) | Viable cell number (106 nuclei/mL alginate) | Function (μg AFP/24 h) |
---|---|---|---|---|
Unfrozen control | – | 99.5±0.6 | 17.7±0.9 | 15.3±2.8 |
37°C water | 1.75±0.5 | 97.8±0.5*** | 14.4±1.2** | 8.7±1.8* |
20°C water | 2.42±0.5 | 93.2±1.7***# | 14.1±0.9** | 7.5±0.3** |
20°C air | 12.92±0.2 | 92.7±3.1***,# | 9.3±1.0***,##,∼∼ | 6.5±0.9**,# |
4°C air | 24.5±4.7 | 90.9±4.9***,# | 8.3±1.4***,###,∼∼ | 5.8±0.5**,# |
ELS were cooled in cryovials using the EF600. The rate of cooling was 1°C/min and cholesterol was used as ice nucleant in all samples. Following cooling, the cryovials were warmed using four different methodologies: 37°C water; 20°C water; 20°C air; and 4°C water to obtain a range of warming rates. The times taken to thaw the cryovials using these four methodologies is given in column 2 (n=2, mean±range). ELS recovery (viability, viable cell numbers, and function) 24 h after thawing was compared to unfrozen control. These data demonstrate that ELS recovery is greatest when rapid warming rates are applied. n=5±SD. *p<0.05, **p<0.01, ***p<0.005 compared to unfrozen control. #p<0.05, ##p<0.01, ###p<0.005 compared to ELS thawed in 37°C water. ∼∼p<0.01 compared to ELS thawed in 20°C water.