Introduction: Embryonic stem cells (ESC) can be produced by isolating and culturing of cell mass (ICM) from blastocysts in specific conditions. ESC are used as research tool for production of transgenic animals, chimeras, cloning and to study embryo development. Simultaneous production of blastocysts and feeder layers is essential for production of ESC. However, produced blastocysts can be vitrified and used at appropriate time. The aim of this study aws to evaluate the mean number and percentage of cells survival in ICM post vitrification and immunosurgery.
Materials and methods: After in vitro maturation and fertilization of immature bovine oocytes, embryos were co.
300 blastocysts were selected and divided into two groups. The blastocusts in one group were used as control, and the blastocysts in the other group were vitrified (Ethylene glycol 40%, 18%, Ficoll and 0.3 M sucrose). After thawing, embryos were culture for 24h and re – expanded embryos, along with the blastocysts in the control group were used for immunosurgery. Call survivals were assessed by trypan blue staining.
Results: The percentage live call of ICM from day 7 blastocusts in control and vitrified group are 96% and 85% respectively and the mean numbers of calls of ICM are 17.4 and 14. The percentage live call of ICM from day 8 blastocysts in control and vitrified group are 95 and 82% respectively and the mean numbers of calls of ICM vitrified and control are 18.6 and 15. The percentage live call and mean number of ICM is significantly different between the group for both day 7 and 8 blastocysts.
Conclusion: Vitrification significantly reduces percentage live cells and the mean unmber of ICM and therefore, it is better to use fresh blastocysts for production of ESC.