Some factors affecting successful vitrification of mouse blastocysts.

The effects of temperature and exposure time to vitrification solutions on In vitro survival of mouse blastocysts were investigated. Blastocysts were first exposed for 10 min to vitrification Solution 1 (VS1) containing 10% glycerol-20% 1,2 propanediol in phosphate buffered saline (PBS), then to vitrification Solution 2 (VS2) with 25 % glycerol-25% 1,2 propanediol for various periods either at room temperature or at 4 degrees C. At room temperature survival dropped quickly, while at 4 degrees C an increase in survival was observed. It is concluded that the viability of mouse blastocyts after vitrification is dependent on the temperature and duration of equilibration in vitrification solutions.