This chapter focuses on the effects of using different types of a physical device, the carrier tool, to carry or enclose the cellular sample in the process of vitrification of human oocytes. It discusses the effectiveness and safety of various tools used in vitrification to hold the oocytes during cooling, storage, and warming. Cooling and warming rates play a critical role in the success of vitrification in assisted reproductive technology (ART) and, in particular, with human oocytes, which appear to be more sensitive to cryopreservation than preimplantation embryonic stages. Cryostorage is the only situation in ART where numerous samples from multiple patients are pooled together in a common liquid environment. Ethylene glycol is a standard part of all present vitrification protocols. Combinations of cryoprotectant (CPAs) have been tested, and finally a mix of ethylene glycol and dimethyl sulfoxide seems to be the most popular choice.