TABLE 7.
Optimal cooling rates (CR) from equilibration temperature (ET) to holding temperature (HT) and survival rates of rumen ciliates after 2 weeks in liquid nitrogen (n = 9)a
| I. prostoma (44,880 ± 3,966) |
D. ruminantium (278,666 ± 27,438)
|
E. ecaudatum caudatum (83,325 ± 7,855)
|
P. multivesiculatum (12,920 ± 1,074)
|
E. maggii (97,502 ± 4,050)
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| ET → HT (°C) | CR (°C/min) | ET → HT (°C) | CR (°C/min) | ET → HT (°C) | CR (°C/min) | ET → HT (°C) | CR (°C/min) | ET → HT (°C) | CR (°C/min) |
| 25 → −4.5* | 9.5 | 24 → −6* | 8.5 | 23.5 → −7.5* | 8.3 | 25 → −5* | 9.3 | 23 → −7* | 9.3 |
| −1.5** → −4 | 1.0 | −2.5** → −4 | 0.4 | −3.5** → −4 | 0.2 | −3** → −4 | 0.3 | −3** → −4 | 0.5 |
| −4 → −8 | 2.1 | −4 → −8 | 2.2 | −4 → −8 | 1.5 | −4 → −8 | 2.3 | −4 → −8 | 1.9 |
| −8 → −19 | 5 | −8 → −19 | 5.7 | −8 → −19 | 5 | −8 → −19 | 5.7 | −8 → −19 | 5.5 |
| −19 → −23 | 3.1 | −19 → −23 | 4 | −19 → −23 | 2.3 | −19 → −23 | 3.3 | −19 → −23 | 4 |
| −23 → −25.5 | 0.9 | −23 → −25.5 | 2.5 | −23 → −25.5 | 0.9 | −23 → −25.5 | 1.8 | −23 → −25.5 | 2.5 |
| −25.5 → −29 | 0.7 | −25.5 → −29 | 0.9 | −25.5 → −29 | 0.6 | −25.5 → −29 | 0.9 | −25.5 → −29 | 1.6 |
| −29 → −30 | 0.4 | −29 → −30 | 0.4 | −29 → −30 | 0.2 | −29 → −30 | 0.3 | −29 → −30 | 0.6 |
a
The times from ET to extracellular ice nucleation temperature (∗) were 3.1, 3.5, 3.7, 3.2, and 3.2 min, respectively; the times from after extracellular ice nucleation temperature (∗∗) to HT were 18.2, 15.5, 21.2, 16.1, and 11.7 min, respectively. The number of cryopreserved cells is shown for each species.