The radical strategy of vitrification results in the total elimination of ice crystal formation, both within the cells being vitrified (intracellular) and in the surrounding solution (extracellular). The protocols for vitrification are very simple. They allow cells and tissue to be placed directly into the cryoprotectant and then plunged directly into liquid nitrogen. To date, however, vitrification as a cryopreservation method has had very little practical impact on human-assisted reproduction. This may be due to the wide variety of different carriers and vessels that have been used for vitrification. Second, many different vitrification solutions have been formulated, which has not helped to focus efforts on perfecting a single approach.
On the other hand, the reports of successfully completed pregnancies following vitrification at all pre-implantation stages is encouraging for further research and clinical implementation.