Dear Sir. Concerning your issue about the storage of DNA solutions. In general, there are four broad strategies for long-term DNA preservation:

Room temperature on a ‘dry’ solid matrix

–20°C

–80°C

–196°C (storage in liquid nitrogen)

Two of these methods, dried and stored at room temperature and storage at –196°C, share a common mechanism where the DNA is maintained in a glassy (or vitreous) state. In the glassy state, molecules lose the ability to diffuse such that the movement of a proton is estimated to be approximately one atomic diameter in 200 years, thereby preventing chemical and nuclease degradation. If moisture is added to the ‘dry state’ or the temperature is raised above the glass transition temperature of water, movement and reactivity of protons is re-established and damage to the DNA can occur. I think the following below links may help you in your analysis:

https://www.ogt.com/resources/literature/403_dna_storage_and_quality

https://www.birmingham.ac.uk/Documents/college-mds/facilities/crf/scientists/dna-preservation.pdf

http://www.nbpgr.ernet.in/Portals/6/DMX/GENOMIC_RESOURCES/DNA%20storage%20methods-principles%20and%20protocols.pdf

https://www.scientistsolutions.com/forum/dna-pcr-real-time-pcr-assay-development/optimal-genomic-dna-storage-conditions

Thanks