Vitrification of Bovine Blastocysts on a Membrane Filter Absorbing Extracellular Vitrification Solution1

The purpose of this study was to test the hypothesis that an extracellular vitrification solution might be unnecessary after equilibration of bovine blastocysts with a vitrification solution. We assessed hatching in culture and the development to normal calves of bovine blastocysts vitrified on a nitrocellulose membrane filter that absorbed extracellular vitrification solution. Twenty in vitro produced bovine blastocysts were vitrified. All embryos were collected after warming and classified as excellent at the start of culture and all hatched between 48–96 h of culture. Transfer of three vitrified blastocysts derived in vivo given to three recipients resulted in the birth of one healthy calf on December 3, 2004. These results indicate that an extracellular vitrification solution is unnecessary after equilibration of embryos and that this new method of vitrification of embryos on a membrane filter is useful for the cryopreservation of bovine blastocysts.