Vacuum Drying Maintains the Integrity of DNA and Protects the Stability of PCR Amplification under Accelerated Aging

Abstract DNA, with its advantages such as ultrahigh storage density, low energy consumption, and ultralong potential lifespan, has become a new generation of storage medium with great development potential. The stability of DNA storage directly determines the reliability of information retrieval. Conventional cryopreservation not only incurs high costs but also leads to DNA degradation over long-term storage. Although current DNA protection methods can delay degradation to some extent, they can hinder DNA release and interfere with downstream PCR amplification and sequencing processes. In this study, solid DNA samples were prepared using vacuum drying without exogenous additives, and accelerated aging experiments were conducted at 70 °C to investigate the integrity of DNA and the stability of PCR amplification. We found that vacuum-dried DNA maintained excellent integrity after being heated for 40 h. DNA heated for 0–30 h showed no significant difference in cycle threshold (Ct) values compared with the unheated control, even after 1000-fold dilution. A significant increase in the Ct value was observed only under critical conditions, in which the DNA sample was heated for 40 h and diluted 1000 times. Under different drying temperatures, the effects of 50 °C vacuum drying and lyophilization on protecting DNA stability are comparable. Our research provides important insights into the storage of long templates and the preservation of nucleic acid samples in fields such as medicine and forensic science.