Chapter 23: Low Temperature Storage – Cool, Cold, Frozen, Ultra, Cryo

Frank P. Simione, American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Virginia 20110-2209

Moisture and temperature are key contributors to deterioration of collection holdings making low-temperature storage critical for preservation. Low temperatures range from those just below the comfort temperature for humans, i.e. approximately 20°C (68oF) to cryogenic temperatures as low as -196°C (-321oF) when using liquid nitrogen. Understanding low temperatures and how they can be achieved, as well as the relationship to moisture, is important when choosing and utilizing the optimal storage method. Facilities and equipment that provide storage at these temperatures pose challenges in design, construction, and maintenance as well as collection access. Investment in appropriate facilities requires a long-term commitment to adequate funding, and a coherent program for collection tracking and use. Use may involve sample destruction or significant modification due to exposure to temperatures outside the optimum range for preservation. The safety of those handling materials at temperatures below freezing must also be considered.

Key words:  biological material; cryogenic; cryoprotectant; fluid preservative; ice core; imaging media; low-temperature storage; lyophilization