Table 3.
In vitro development of B6D2F1 oocytes fertilized by ICSI with fresh, frozen, or freeze-dried B6D2F1 spermatozoa
| Sperm treatment | Sperm freezing medium | Sperm storage time, days | No. oocytes injected (No. exps.) | No. (%) oocytes activated* | No. (%) 2-cell embryos | No. (%) blastocysts |
|---|---|---|---|---|---|---|
| Fresh | Hepes-CZB | — | 71 (4) | 71 (100) | 71 (100) | 61 (86)a |
| Frozen and kept at −75°C | EGTA† | Up to 112 | 96 (4) | 95 (99) | 94 (99) | 75 (80) |
| Freeze-dried and kept at 4°C | EGTA | Up to 28 | 158 (7) | 135 (85) | 133 (99) | 96 (72)a |
Statistically significant χ2 comparison:
a
, P < 0.05.
*
Activated oocytes with two pronuclei and the second polar body.
†
Composition of EGTA medium: 50 mM NaCl, 50 mM EGTA, and 10 mM Tris⋅HCl.