Shall I compare thee to a strand of DNA?


For billions of years DNA has been life’s data storage medium. Now, scientists have used DNA to code and store their media and information, from all of Shakespeare’s sonnets to an audio recording of Martin Luther King’s ‘I have a dream’ speech.1

‘If you stick a CD in a box ‘round the back of the sofa it’s good for a couple of years but it might not work three years later,’ explains Nick Goldman of the European Bioinformatics Institute, just outside Cambridge in the UK, whose team performed the work. ‘In 10 years’ time, when you take the box out of the garage, you might not even have a CD player anymore.’

dna storage

DNA's stability makes it an excellent choice for storing data in the long-term © NPG

By contrast, DNA is long lived. Dried DNA can last for years, as Goldman explains: ‘They go drilling cores in Antarctica and the get bacteria out from 100m down in the ice. They reckon those are millions of years old and they get DNA out of them.’ That stability, along with the increasing developments in DNA production and sequencing make the idea of DNA information storage an attractive option.

Even though we talk about the letters of DNA, there are only four bases (A, C, G and T), so there are not enough letters to spell out even a simple sentence. Instead, Goldman’s group converted data into binary and then each byte was converted using various codes and information theory algorithms into a DNA sequence that was very information dense but avoided runs of the same base, known as homopolymers. ‘Both the writing and reading techniques are more prone to making mistakes if there’s a run of the same DNA base in a row,’ explains Goldman. ‘If you’ve got two or three or four As – adenines – in a row it’s harder to read that back exactly right.

A technique whose time has come

In August of last year, a US group of scientists also published a paper demonstrating information storage in DNA.2 But while the two groups, working simultaneously, had some similar ideas their approaches are different. Goldman’s work focuses on reducing errors by using what are called error correcting codes, to avoid issues like homopolymers, while the alternative approach was careful to avoid sequences within the DNA that could result in secondary structures and folding within the polymer. It was these secondary structures that caused the only read errors in Goldman’s work and he is confident that further work can avoid these in future.

‘I think it’s very important and somewhat undervalued how important it is, especially for a new field, to have two groups that are independently doing it,’ says George Church, a geneticist at Harvard University, who is an author on the US paper. This new field, he says, is only really beginning now that the technologies are good enough to read the DNA.

But is DNA storage just for large archives? As the costs of DNA reading and writing technologies comes down both Church and Goldman suggest that DNA might be the read only medium of choice. In fact, both Goldman and Church suggest that DNA-based information storage might just be the commercial push needed to really lower the cost of DNA writing, much as medicine has pushed down the cost of sequencing.

For Sriram Kosuri, who worked with Church on the 2012 paper, the value of both of these pieces of work is that they get people to think differently about data storage. ‘We’re reaching a limit on how much we can store on a surface,’ he explains, mentioning the current world record of a 12 atom transistor. ‘Both of these papers blow that out of the water in terms of density and longevity.’ And that polymer might not be DNA, but another polymer that’s easier to read and synthesise and less prone to enzymatic digestion. ‘We’re using DNA in its rawest form, but I think in the future we can imagine using something very different,’ he concludes.


Related Content

Chemistry World podcast - March 2013

13 March 2013 Podcast | Monthly

news image

Mark Mascal talks about bio-derived chemicals, John Lindon introduces the Phenome Centre and the team cover the latest news

Cutting edge chemistry in 2013

12 December 2013 Research

news image

We take a look back at the year's most interesting chemical science stories

Most Read

Better batteries with pure lithium anodes

28 July 2014 Research

news image

Protective carbon nanosphere coating overcomes lithium problems, pointing the way to improved capacity

Takeover battle pushes Allergan to cut R&D jobs

28 July 2014 Business

news image

Besieged by serially acquisitive Valeant, the Botox maker will lay off 1500 staff to propel earnings growth

Most Commented

Bubble wrap could send lab costs packing

23 July 2014 Research

news image

Potential bubbles up across wide range of uses as storage and test vessels, especially for poor countries

Relativity behind mercury's liquidity

21 June 2013 Research

news image

First evidence that relativistic effects are indeed responsible for mercury's low melting point