I try to resist computer-to-human analogies like “the brain is just an organic computer!” They’re facile and, ultimately, inaccurate. One role of DNA, however, is to act as a kind of data storage. It’s a wild oversimplification to compare genetic code to computer code, but there’s a kernel (geek pun: sorry) of truth in there. DNA can indeed compress a mind-blowing amount of information into an extremely small space. As we reach the limits of silicon and other materials, DNA could be at the heart of the next great computer revolution.
An article in Science is outlining how that next revolution may unfold. As the story observes, it’s possible to fit the entire text of every book in the Library of Congress on a milligram of DNA, and a team led by George Church, a synthetic biologist at Harvard Medical School, is showing the way. Church’s group appears to be the first to move beyond the merely theoretical by storing the contents of a genetics textbooks on less than 1,000,000,000,000th of a gram (a picogram) of DNA.
The problem has been with the nature of living cells. They die, the replicate, they can mutate. In short: they’re too unstable to be used for data storage using any known methods. Church got it to work because he didn’t use living cells:
Instead, an inkjet printer embeds short fragments of chemically synthesized DNA onto the surface of a tiny glass chip. To encode a digital file, researchers divide it into tiny blocks of data and convert these data not into the 1s and 0s of typical digital storage media, but rather into DNA’s four-letter alphabet of As, Cs, Gs, and Ts. Each DNA fragment also contains a digital “barcode” that records its location in the original file. Reading the data requires a DNA sequencer and a computer to reassemble all of the fragments in order and convert them back into digital format. The computer also corrects for errors; each block of data is replicated thousands of times so that any chance glitch can be identified and fixed by comparing it to the other copies.
If your first thought is, “That sounds awesome…ly expensive!” you’re right. No one is about to fire up the DNA sequencer to store their vacation snaps. One constant with most technology, however, is that it gets cheaper, smaller, and better with time. Down the road, a DNA drive could be as ubiquitous and a flash drive.
There is something big on the horizon at the juncture between computing and DNA. Programmers are eyeing those four-letter DNA sequences and wondering what they may be able to do that binary cannot. No one really knows. None of this is particularly problematic ethically, since the “DNA” isn’t the real, living thing. But what if it was? What if it was possible to store your data in your own body? How would that be any different than just getting a tattoo?
Also check out … Get Offa My Cloud.