Table 1 Comparison of different freeze-thaw methods for extracting of C-PC.
Protocol | Primary freezing | Intermediary freezing | Extended freezing | Thawing |
|---|---|---|---|---|
1 | — | −5 °C, 90 min | −20 °C, 3 h | +35 °C, 1 h |
2 | −20 °C, 10 min | −5 °C, 1 h | −20 °C, 3 h | +35 °C, 1 h |
3 | −20 °C, 2 min | −5 °C, 1 h | −20 °C, 3 h | +35 °C, 1 h |
4 | Liquid nitrogen, 2 min | −5 °C, 1 h | −20 °C, 3 h | +35 °C, 1 h |
5 | — | — | −70 °C, 4 h | +4 °C, 4 h |
6 | — | — | −20 °C, 4 h | +4 °C, 4 h |
