Biorepositories are tasked with the care and storage of priceless collections of biological specimens. Critical to the success of biorepository operations is the safe, secure, viable storage of the specimens entrusted to its care. The primary means by which this is accomplished is to ensure proper function of ultralow freezers. For a large biorepository this involves the tracking and monitoring of hundreds of freezers. Biorepository procedures typically require recording of the temperature of each freezer on a daily basis. At the Central Repository of the National Cancer Institute in Frederick, Maryland, temperature monitoring has been taken one step further. New procedures utilize the in-house 24-h temperature monitoring system to produce daily printouts of the fluctuation of temperature with time. These graphs are reviewed, and based upon an understanding of freezer compressor cycles are used to identify potential problems with freezer function. These new procedures, which can be used to predict failure...