Evaluation of Storage Solutions for DNA Preservation in Various Conditions

Abstract

DNA should be protected from factors such as temperature fluctuation, hydrolysis, and oxidative damage, to be preserved intact. Thus far, DNA has been conventionally stored in freezers to avoid the influence of these factors. However, as the required storage time and number of samples increase, so do the spatial and financial burden. DNAstable and DNAstable Plus are commercial solutions for long-term storage of DNA at room temperature. In this study, DNA extracted from human blood was stored at different temperatures (room temperature, 60 °C, −80 °C, −20 °C, and 4 °C), under hydration and illumination conditions, and with or without long-term storage solutions. After 1, 3, 6, and 12 months of storage, we analyzed the quantity and preservation of STR loci of the stored DNA. Storage of DNA for 1 year at 60 °C using DNAstable® Plus, simulating 16 years of storage at room temperature, had a preservative effect similar to that of freezing in dried state. On the other hand, DNAstable® was inefficient compared to conventional methods. Storage at ambient temperature using DNAstable® Plus thus presents a cost- and space-effective alternative for long-term storage, even for concentrations of DNA lower than 0.5 ng/μL.