Chain and conformation stability of solid-state DNA: implications for room temperature storage

Area of Science:

• Biochemistry
• Molecular Biology
• Materials Science

Background:

• Dehydrated DNA storage at room temperature is of significant interest.
• Limited understanding exists regarding the chemical and structural stability of solid-state DNA under ambient conditions.

Purpose of the Study:

• To investigate the impact of atmospheric water and oxygen on the stability of dehydrated DNA at room temperature.
• To assess the degradation rates and structural integrity of DNA under various storage conditions.

Main Methods:

• Measurement of DNA chain-breaking rates at elevated temperatures (70-140°C) following Arrhenius' law.
• Extrapolation of degradation rates to room temperature (25°C).
• Denaturation experiments to evaluate DNA secondary structure preservation and restoration upon rehydration, with and without trehalose.

Main Results:

• Solid-state DNA degradation at room temperature is significantly influenced by atmospheric water and oxygen, leading to aggregation.
• Extrapolated degradation rates at 25°C suggest approximately 1-40 cuts per 10^5 nucleotides per century, though these are tentative.
• DNA secondary structure is generally preserved or restorable upon rehydration, except for small fragments (<500 bp) which may undergo irreversible denaturation, a process slowed by trehalose.

Conclusions:

• Complete protection from water and oxygen is essential for effective room temperature storage of dehydrated DNA.
• While extrapolation suggests slow degradation, real-world conditions with contaminants and additives may alter these rates.
• Trehalose can mitigate irreversible denaturation in smaller DNA fragments during storage.