Don't have a hard drive? Now store data in bacteria!
Talk about data storage devices and the first thing most people think of are the reassuring little rectangular structures that have become a crucial part of our lives - the hard drive. Now, there's a newer, more radical alternative to the hard drive - living bacteria. Yes, it turns out that live bacteria can store data in their cells.
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A team of Harvard scientists, led by geneticists Seth Shipman and Jeff Nivala have published a paper in the Science Journal that explored - with a fair degree of success - a method to change living bacterial cells into microscopic hard drives. The technique they used practically fooled the bacteria into copying actual computer code into their DNA without compromising their own cellular activities. Not only this, the bacterial cell passes the data stored onto their 'progeny' - that's basically like 'backing up' your data, except in a cellular fashion! Scientists have attempted this before but with synthetic DNA, and this experiment also allows the transfer of a 100 bytes of data, almost ten times more than possible with artificial DNA.
"We write the information directly into the genome. While the overall amount of DNA data we have currently stored within a genome is relatively small compared to the completely synthetic DNA data storage systems, we think genome-based information storage has many potential advantages," Nivala told Gizmodo, clarifying that, "Depending on how you calculate it, we stored between about 30 to 100 bytes of information. Which is quite high compared to the previous record set within a living cell, which was ~11 bits."
The kind of bacteria one uses is important going forward. For this particular experiment researchers used E. coli that clocks in a fairly respectable storage of 100 bytes. However, certain bacteria, such as Sulfolobus tokodaii may be capable of storing thousands of bytes.
How the experiment really worked
The technique that's behind this whole project is called CRISPR, a gene editing technique that's created a major buzz in the field of genetic engineering - it's been the focus of the fight with retroviruses like HIV to the birth of monkeys with customised mutations.
How CRISPR works is a slightly complex and really intriguing. Check out this MIT video to get a lowdown. Clustered Regularly Interspaced Short Palindromic Repeats, or CRISPR, has been intriguing scientists for quite some time now, since the 1980s, in fact. There's an important secondary aspect to this technique called Cas (CRISPR-associated proteins) - the Cas helps to targetedly slice DNA of any invading virus. Both work in tandem to ward off unwanted viruses, and have now become intrinsic to the storage of data.
Whenever a virus attacks a bacterium, CRISPR helped memorise the event in the DNA, for future reference in case of renewed attacks. How? By storing microscopic segments of the viral DNA itself, called spacers. The Harvard team figured that the temporal rearrangement of spacers could form the basis of a 'molecular recording device.' Next, they created something similar to 'fake viruses' that were, in fact, strings of data. So when they were introduced into the bacteria, the fake viruses (which is in fact, the data) got 'memorised' - in effect, stored by the bacterial cell. That's basically how data can be stored in future.
"These experiments lay the foundations for a recording system that could be used to monitor molecular events that occur over long time periods," Nivala told Gizmodo. "For instance, it could eventually help us answer questions like what happens to the gene regulation inside a cell as it goes from a healthy to disease state. Or it could also be used to record information on the cell's outside environment, for example the presence of specific chemicals, toxins, or pathogens."
Of course it isn't a perfect system. The CRISPR technique hasn't worked in all of the bacteria tested, only some. Also, only parts of the code DNA containing any data are snipped - in order to copy the whole set of data one would need to copy the same code DNA into a larger population of bacteria. The size of the data is also far from what can be deemed really significant. But, 100 bytes is enough for a haiku, for now. Here's an imaginative one from the Mother Nature Network:
your thumb might someday become
a real thumb drive".