CLOSING IN ON AN ERA OF DNA DATA STORAGE
Technology
The idea of DNA as a source of data storage, by virtue of its stunning prowess in nursing torrents of information accurately, has long been touted by scientists and researchers who look for a substitute to the current, relatively feeble hard-drive technology. But can something 3.8 billion years old really provide an avenue leading to the solution of a modern-day problem?
Humans have always sought and adopted different information-storage systems as time has ticked by: from animal skins, wood tablets, books to finally hard drives. Until recently, these hard-drives were considered a miracle of modern technology — for a mere $50, anyone could comfortably get to store the contents of, let’s say, the entire Bodleian Library in Oxford into a packet sizing only 3.5 inches. But, as often is the case, natural selection has knocked humans’ best efforts into a cocked hat, as recently it has transpired that DNA, the life’s information-storage tool, which predates all other information-storage systems, is the real diamond in the rough.
Like all other great ideas, the idea to use DNA as a data storage source also took roots in a — pub. Yes, you read that right. Nick Goldman and Ewan Birney, of the European Bioinformatics Institute (EBI) near Cambridge, were unwinding themselves when they began contemplating what approach they could take to archive the mounting swathes of data their research was generating. Over a few beers, the duo thought whether artificially constructed DNA could be a way. Next, it only took them some more drinks and much scribbling on beer mats to eventually mold this revolutionary reflection into the bones of a workable scheme.
Soon afterwards, this idea picked up quick steam. Naturally, DNA uses four chemical bases to encode information: adenosine (A), thymine (T), cytosine (C ) and guanine (G). Digital information can be embedded into DNA by mapping binary 1s and 0s used by computers onto these bases. For instance, A and C may denote binary 1, while G and T may signify binary 0. Similarly, these four bases can be assigned other functions as well to relay different types of information. Recently, Seth Shipman — a geneticist at Harvard Medical School — pioneered storage of a video inside DNA. He, accompanied by his colleagues, started by fabricating synthetic strands of DNA and encoded in its bases — A, T, C and G — the positions and pixels found in a video of a galloping horse shot in 1880’s. They fed these strips of DNA to E.coli bacteria that devoured these and added to its own genome, treating them as a marauding virus. These bugs were then left in a dish for a time spanning a week, allowing them to undergo growth and cell division to split up into new bacterial cells. Ultimately, these bugs were collected to retrieve the video information from their genetic code, and it was discovered that even after dividing their DNA retained it with 90% accuracy! Staggering it is, right?
But honestly, there is more to the feat than just showing off. It is the storage capacity of DNA that lures. In contrast to the current magnetic tapes (hard drives), which are cheap but occupy a lot of physical space, DNA can swallow humongous amounts of data because of its exceptionally high density. How dense it is exactly? Well, all the world’s current data storage needs for a year could be well satisfied by only a cube of DNA measuring one meter on a side!
“Today’s technology is already close to the physical limits of scaling,” says Victor Zhirnov, chief scientist of the Semiconductor Research Corporation. “DNA has an information-storage density several orders of magnitude higher than any other known storage technology.”[1]
Another characteristic of DNA that is prized is its prodigious stability. Although magnetic tapes tend to decay with the interminable slip of time and must be replaced after every few years, data in DNA remains readable even after thousands of years as has been proved by its recovery from a fossil horse that lived more than 500,000 years ago. This attribute makes it specially enticing to the scientists and researchers who are increasingly concerned about the safekeeping of their huge research data in the long run.
However, these aides come riveted with a covert price tag. The reason is not so much of technological difficulty as the cost. DNA synthesis companies, like Twist Bioscience, charge 7 to 9 cents per base, which essentially means that encoding a single gigabyte of digital information in DNA would run up a bill of several million dollars. or in more lucid terms, a single minute of a high-quality stereo sound could be stowed for just under $100,000. On the other hand, a hard-drive completes the same job for less than a cent. Furthermore, the relatively slow speed at which the data can be read back from DNA and written also presents a downside. It takes a span of weeks to just reconstruct a few number of files, making the overall process advance at a snail’s pace. Nevertheless, this is not much of a problem as better equipment does guarantee a better speed.
Conclusively, it is quite evident that in order to translate the promise into a sound reality, DNA data-storage technology requires some refinement. To this end, several companies, such as Catalog, are seeking different approaches to maximize the productivity of this technology to make it ubiquitous. Thereby, it is right to declare that we are surely closing in on an era of DNA data storage.
[1] “The Rise of DNA Data Storage | WIRED,” accessed May 30, 2021, https://www.wired.com/story/the-rise-of-dna-data-storage/.
Credits:
- Fig.1 provided by Flickr, https://creativecommons.org/licenses/by/4.0/legalcode
