Spindle configuration and developmental competence of in vitro-matured bovine oocytes exposed to NaCl or sucrose prior to Cryotop vitrification.

In the present study we examined whether exposure to high concentrations of NaCl or sucrose before vitrification improves the cryotolerance of in vitro-matured bovine oocytes. In Experiment 1, oocytes were exposed to different concentrations of NaCl (375-1517 mOsm) or sucrose (375-812 mOsm) for 1h. On the basis of the results of this experiment, in Experiment 2 oocytes were exposed to 0.