DNA has a high data density and can be easily copied. Thus, DNA data storage could replace traditional long-term storage approaches, e.g., magnetic tape. However, the synthetic DNA used for this needs to be protected from degradation to provide reliable long-term storage. DNA recovered from fossils shows that encapsulation in inorganic materials can offer robust protection. However, DNA storage methods that try to replicate this effect are limited by low DNA loading capacities so far.

Robert N. Grass, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland, and colleagues have used earth alkaline salts as a protective inorganic matrix for DNA protection that allows high DNA loadings (> 10 wt%). The team tested calcium phosphate, calcium chloride, and magnesium chloride. They used a synthetic 148mer double-stranded DNA sequence as a model and dried solutions of the DNA and the salts using methods such as vacuum centrifuge drying or freeze-drying.

The resulting solids were subjected to an accelerated aging process to test the DNA stabilization. Samples with different DNA loadings were subjected to 60–70 °C at 50 % relative humidity for up to 33 days, after which the amount of intact DNA was measured. The researchers found that all three salts provide a significant DNA stabilizing effect even at high DNA loadings. The DNA is easy to load, but also easy to retrieve by rehydration and read out . These processes could also be automated to provide simple data storage.

• Stabilizing synthetic DNA for long-term data storage with earth alkaline salts,
  A. Xavier Kohll, Philipp L. Antkowiak, Weida Chen, Bichlien Nguyen, Wendelin Jan Stark, Luis Ceze, Karin Strauss, Robert N. Grass,
  Chem. Commun. 2020.
  https://doi.org/10.1039/d0cc00222d