Microsoft is buying ten million strands of DNA from biology startup Twist Bioscience to investigate the use of genetic material to store data.

The data density of DNA is orders of magnitude higher than conventional storage systems, with 1 gram of DNA able to represent close to 1 billion terabytes (1 zettabyte) of data. DNA is also remarkably robust; DNA fragments thousands of years old have been successfully sequenced.

These properties make it an intriguing option for long-term data archiving. Binary data has already been successfully stored as DNA base pairs, with estimates in 2013 suggesting that it would be economically viable for storage of 500 years or more.

The big difficulty with DNA storage is reading and writing. The writing is done by Twist; the company can produce custom strings of DNA using a machine it constructed. The company's main customers are research labs that insert custom genetic material into microbes to produce organisms that can perform useful chemical processes, such as producing desirable nutrients. Using DNA for data storage is a new field for the company. A custom DNA sequence costs about 10 cents per base, with Twist hoping to get that cost down to 2 cents.

Reading the data uses genetic sequencing. The costs of this have dropped substantially over the last 20 years. The human genome project, which ran from 1990 to 2003, cost about $3 billion. The same task can now be done for about $1,000.

Those costs, though dropping, mean that commercial viability of synthetic DNA storage is still some way off, but the technology itself works. Microsoft says that its initial trials with Twist have shown that the process allowed full retrieval of the encoded data from the DNA. If the technology can be made cheap enough, it means that one day long-term data archiving could use the same technology as life itself.