Achieving temperature stability for storage of biological samples in an autodefrost freezer

Abstract

Abstract OBJECTIVE To assess the temperature stability of an autodefrost freezer commonly used in veterinary practices, whether the use of a Styrofoam cooler within the freezer provides temperature stability, and the ease of use of a remote monitoring system for the notification of temperature elevations. ANIMALS None. METHODS Temperature in the freezer and 2 Styrofoam coolers were assessed with remote monitoring thermometers every 15 minutes. Temperature values were monitored from October 11 to December 18, 2023 (for a 68-day period). Data analysis focused on temperatures for the freezer exceeding 0 °C and the elevations in temperatures within the coolers relative to the freezer. RESULTS The freezer had an increase in temperature approximately every 16 hours. Over 68 days, the freezer had a temperature greater than 0 °C 27 times, representing 26 separate elevations. The Styrofoam coolers within the freezer never registered a temperature higher than −5 °C. Elevations in temperature within the freezer were larger in magnitude than temperature elevations within the coolers, which showed smaller-magnitude changes in temperature. CLINICAL RELEVANCE The temperature stability provided by the Styrofoam cooler would avoid potential freeze-thaw cycles of any stored biological samples. Additionally, the remote temperature monitoring system is easy to install and monitor, providing peace of mind to practice management.