HONG KONG: Taking inspiration from the way fossilized bones can preserve genetic material for hundreds of thousands of years; researchers at ETH Zurich have developed a “synthetic fossil” by writing digital information on DNA and then encapsulating it in a protective layer of glass.
Most of our digital data is stored with technology that is designed to work in the short term, but which can’t really stand the test of time. Standard hard disk drives won’t last more than a few decades and are subject to damage from high temperatures, moisture, magnetic fields and mechanical failures. Even solid state drives, which perform better and are less susceptible to mechanical issues, will lose their data if they go unpowered for more than a few months.
One interesting solution could be to store digital data using strands of DNA. As far-fetched as this may sound, there are a couple of very good reasons that make this an attractive proposition. Firstly, DNA can store information with a data density so high that it can be hard to fathom: a single living cell can contain millions of nucleobases and each can represent at least one bit of information, for a data density approaching one petabyte (million gigabytes) per cubic millimeter. Add to this the fact that under the right conditions fossils can preserve genetic material for millions of years, and you have the perfect candidate for long-term data storage. This is exactly what Dr. Robert Grass and team at ETH Zurich are trying to achieve.
As you’ll remember from high school biology, DNA is encoded by four nucleobases, meaning that each of them can, in theory, represent up to two bits of information. After limitations dictated by the technical challenges of synthesizing and sequencing nucleotides, and with the addition of redundant bits (which make up 35 percent of total data) to protect against data corruption, the final rate is an impressive 1.2 bits of useful data for each nucleotide.
Dr. Grass and team began their experiment by storing 83 kilobytes of information (Switzerland’s Federal Charter of 1291 and Archimede’s The Methods of Mechanical Theorems) inside 4,991 DNA segments, each 158 nucleotides long. Then, to protect the DNA from degenerating over time, the researchers created a de facto “synthetic fossil” by encapsulating it in 150-nanometer silica spheres, which prevent the genetic material from chemically reacting with the environment. To read the data back, the nanospheres need to be exposed to a fluoride solution which dissolves the silica but leaves the DNA intact.
