Current data storage technology uses hard drives and data disks to store data at the click of a button. However, just as these methods replaced the magnetic tapes and floppy disks before them, they are likely to be overtaken by updated methods in the future. One such medium being explored is DNA, the molecule that stores the genetic information of biological organisms. Researchers at Columbia University have now discovered a way to engineer living bacteria to store data in their DNA. This is appealing because DNA storage is 1,000 times more dense than the most compact hard disk, enabling storage of huge amounts of data in a miniscule amount of space.
DNA storage has been explored before, but previous methods used very expensive techniques that require breaking up the DNA into small pieces, which are prone to degradation. To develop a longer-lasting, easier-to-encode medium, the researchers incorporated electrical inputs and CRISPR biology to encode data into the DNA of living E. coli bacteria. They engineered the bacteria to increase the number of copies of a specific sequence, called pTrig, in response to electrical signals. Once amplified, the pTrig sequence is then incorporated into the DNA. If there is no electrical signal, then a different reference sequence is incorporated into the DNA. To mimic the binary code of computers, the presence of an electrical signal represented a 1, while the lack of an electrical signal represented a 0. This binary code could then be read out by looking at the pattern of pTrig sequences versus other reference sequences. Using this method, the researchers encoded 72 bits of data to spell “hello world!”. They also mixed their encoded E. coli into soil with other microbes and were able to sequence the mix and recover their message. Since the DNA is protected by the cell, it does not suffer from degradation over time.
While this study accomplished an amazing feat by encoding living organisms with reliably recoverable binary code, the methodology is still in its early days and certainly cannot compete with current memory storage systems. Scientists must also figure out how to overcome the issue of preventing the message from mutating over time, since bacteria mutate as they replicate; in their experiments, the data was only stable for 60 generations. However, once these barriers are crossed, this method may offer an interesting way to add extra security by hiding data within a natural microbial community.
Dr. Harris Wang is an Associate Professor in the Department of Systems Biology and Department of Pathology and Cell Biology at Columbia University Medical Center. Dr. Sung Sun Yim is a postdoctoral fellow in the lab.
Managing Correspondent: Lauren Davancaze
Press Articles: “Scientists ‘program’ living bacteria to store data,” Science
Original Journal Article: “Robust direct digital-to-biological data storage in living cells,” Nature Chemical Biology
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