Table 2.
Predicted sub-zero membrane permeability parameters (Lpg or Lpg[cpa] and ELp or ELp [cpa]) and the optimal rates of freezing for Xiphophorus maculatus sperm cells in the presence and absence of cryoprotective agents (CPAs)
| Assumed inactive cell volume (Vb) | Concentration of CPA (v/v) | Lpg or Lpg [cpa] ×1015 m3/Ns (μm/min atm) | ELp or ELp [cpa] kJ/mol (kcal/mol) | Predicted optimal cooling ratea (°C/min) |
|---|---|---|---|---|
| 0.6 V0 | No CPA | 1.59 (0.0093) | 121.2 (29.0) | 28 |
| 14% glycerol | 0.91 (0.005) | 40.9 (9.8) | 47 | |
| 10% DMSO | 0.99 (0.006) | 67.3 (16.1) | 36 | |
| 0.4 V0 | No CPA | 2.63 (0.015) | 134.9 (32.3) | 26 |
| 14% glycerol | 1.33 (0.008) | 40.8 (9.8) | 47 | |
| 10% DMSO | 1.45 (0.009) | 66.0 (15.8) | 36 | |
| 0.8 V0 | No CPA | 1.20 (0.007) | 175.6 (42.0) | 21 |
| 14% glycerol | 0.68 (0.004) | 66.9 (16.0) | 50 | |
| 10% DMSO | 0.48 (0.003) | 65.6 (15.7) | 36 |
Note that the goodness of fit, R2 value was always greater than >0.98.
a
The optimal cooling rate was predicted using Eq. (4) in which ELp or ELp [cpa] are in kcal/mol, Lpg or Lpg [cpa] are in μm/min atm and SA/WV is 15.15 μm−1.