© AlamyInternet pioneer Vint Cerf has warned of a 'digital dark age' descending as computer hardware and software becomes obsolete.
DNA could be used to store digital information and preserve essential knowledge for thousands of years, research has shown.

Scientists exploring the archiving potential of DNA conducted a test in which error-free data was downloaded after the equivalent of 2,000 years.

The next challenge is to find a way of searching for information encoded in strands of DNA floating in a drop of liquid.

Lead researcher Dr Robert Grass, from the Swiss Federal Institute of Technology (ETH), said: "If you go back to medieval times in Europe, we had monks writing in books to transmit information for the future, and some of those books still exist. Now, we save information on hard drives, which wear out in a few decades."

DNA has a "language" not unlike the binary code used in computers, said Dr Grass. While a hard drive uses zeros and ones to represent data, the DNA code is written in sequences of four chemical nucleotides, known as A,C,T and G.

But DNA can pack more information into a smaller space, and also has the advantage of durability.

In theory, a fraction of an ounce of DNA could store more than 300,000 terabytes of data, said Dr Grass. And archaeological finds had shown that DNA dating back hundreds of thousands of years can still be sequenced today.

© AlamyDNA 'language' is said to be similar to binary code used in computers.
Dr Grass's team managed to encode DNA with 83 kilobytes of text from the 1921 Swiss Federal Charter, and a copy of Archimedes' famous work The Method dating from the 10th century.

The DNA was encapsulated in silica spheres and warmed to nearly 71C for a week - the equivalent of keeping it for 2,000 years at 10C. When decoded, it was found to be error-free.

The scientists are now working on ways to label specific pieces of information on DNA strands to make them searchable.

"In DNA storage, you have a drop of liquid containing floating molecules encoded with information," said Dr Grass. "Right now, we can read everything that's in that drop. But I can't point to a specific place within the drop and read only one file."

DNA storage could be used to preserve troves of historical texts, government documents or entire archives of private companies - all in a single droplet, he added.

The main drawback of the technology was cost. Encoding and saving just a few megabytes of data in DNA currently cost "thousands of dollars", so personal DNA hard drives were unlikely to be within reach of ordinary consumers any time soon.

Internet pioneer Vint Cerf has warned of a "digital dark age" descending as computer hardware and software becomes obsolete.

Speaking at the annual meeting of the American Association for the Advancement of Science in February, he said: "We are nonchalantly throwing all of our data into what could become an information black hole without realising it."