Book written in genetic code opens new possibilities for data storage

An entire book, comprising 53,426 words, 11 images and a computer program, has been encoded into DNA. The data was stored and accurately read back by scientists at Harvard University in the USA.

The scientists' achievement represents 1,000 times more data than has previously been stored on DNA. The researchers say that their work is an early step on the path to storage devices of vastly more capacity than are currently available.

'A device the size of your thumb could store as much information as the whole internet', said Professor George Church, lead author of the study, published in the journal Science.

DNA is a natural information storage system and one gram of DNA can store up to 455 billion gigabytes of information, equal to the contents of over 100 billion DVDs. DNA contains bases, four chemicals that form a code. In living organisms the bases adenine (A), guanine (G), cytosine (C) and thymine (T), encode genes - instructions to make the proteins that we are made of.

The Harvard researchers started with a version of the book which had been transcribed into binary - that is, composed of ones and zeros. They translated the zeros to A or C and ones to G or T. Next they synthesised 55,000 short strands of DNA containing the relevant code. Each strand also contained a marker, or address, to show where it occurred in the book.

The work did not involve living organisms and the strands were stored on glass microchips rather than in cells - the researchers claim that in this form the DNA could be stored for centuries. The scientists then sequenced the DNA and reassembled the contents of the book.

Photographs, books, videos, medical files and financial records are increasingly stored digitally, as computer code. Such information is accumulating at an exponential rate, stretching our abilities to store and archive it. The DNA synthesis and sequencing techniques the Harvard scientists used are a way off being commercially viable but, says Professor Church, 'for some archival problems, this could be the wave of the future'.