Scientists encode entire book in DNA

Scientists have encoded a book in genetic molecules of DNA, paving the way for future data-storage devices with more capacity for their size.

Researchers led by Harvard University molecular geneticist George Church translated the English text of a coming book on genomic engineering into actual DNA or deoxyribonucleic acid.

DNA has long tantalised researchers with its potential as a storage medium: fantastically dense, stable, energy efficient and proven to work over a timespan of some 3.5 billion years.

About four grammes of DNA theoretically could store the digital data humankind creates in one year.

While not the first project to demonstrate the potential of DNA storage, Church's team has encoded 1,000 times the largest amount of data previously stored in DNA.

The researchers used binary code to preserve the text, images and formatting of the book. The density of the bits is: 5.5 petabits, or 1 million gigabits, per cubic millimetre.
While some experimental media - like quantum holography - require incredibly cold temperatures and tremendous energy, DNA is stable at room temperature.

"You can drop it wherever you want, in the desert or your backyard, and it will be there 4,00,000 years later," Church said.

Reading and writing in DNA is slower than in other media, however, which makes it better suited for archival storage of massive amounts of data, rather than for quick retrieval or data processing.

Although other projects have encoded data in the DNA of living bacteria, the Church team used commercial DNA microchips to create standalone DNA.

The team also rejected so-called "shotgun sequencing," which reassembles long DNA sequences by identifying overlaps in short strands.

Instead, they took their cue from information technology, and encoded the book in 96-bit data blocks, each with a 19-bit address to guide reassembly.

Including jpeg images and HTML formatting, the code for the book required 54,898 of these data blocks, each a unique DNA sequence.
The study was published in the journal Science.