Abstract: A closed system cryopreservation device for vitrification of biological specimens includes an elongated body from one end of which extends a frustoconical boss and an elongated cap for sealably enclosing a biological specimen with an elongated hollow chamber. The interior surface of the chamber defines a frustoconical volume corresponding to the frustoconical boss, such that when the boss is inserted into the chamber, substantially the entire interior surface is in contact with the exterior surface of the boss. The device further comprises a substantially uniform coefficient of thermal expansion.