Cryostorage devices and methods

A cryostorage unit, comprising:

• a cryochamber configured to store at least one rack in a cryogenic internal volume defined by the cryochamber, the cryochamber including a cryo-access port at an upper portion of the cryochamber, the cryo-access port being configured to place the internal volume in fluid communication with an ambient space via a port aperture extending through a top cryochamber surface;
• a cork selectively occluding the cryo-access port for resisting ingress of ambient air to the cryochamber;
• and
• a dry air supply device at least partially external to the cryogenic internal volume, the dry air supply device including a dry air supply line in fluid communication with at least a chosen one of the cryogenic internal volume and the cryo-access port;
• wherein the dry air supply device selectively provides dry air to volumetrically prevent intrusion of non-dry air within the chosen one of the cryogenic internal volume and the cryo-access port.