The scientists published their findings on August 16 in the journal Science. In theory, two bits of data could be incorporated per nucleotide, implying that each gram of DNA could store 455 exabytes of data (1 exabyte is 1 million terabytes), which outstrips inorganic storage devices like flash memory, hard disks, and even quantum-computing methods.
Geneticist George Church and his colleagues made significant gains on previous attempts, augmenting it by at least 600 times. For now, this organic storage is still years away as there is no practical way of using it every day. It requires days of lab work to retrieve and store information since DNA strands have to be synthesized or sequenced to read the data.
Other attempts to store information in DNA were held up by difficulties in making perfectly long strands. Shorter molecules are easier to work with. Church et al. kept their storage attempts to a mere 159 nucleotides, and then generated multiple copies of each so that catching and corrections mutations was easier.
In a single strand of DNA, 96 nucleotides represent the encoded data as binary bits. 19 nucleotides show how this data should be ordered and 44 enable easier sequencing. ‘0’ was assigned to A and C and ‘1’ to G and T.
This technique could be used in specialized applications where stored data doesn’t need to be read for a long time. This kind of storage could last centuries, whereas magnetic and optical storage media would be rendered obsolete.
George Church and Sriram Kosuri discuss the benefits of using DNA as a storage medium and the approach they developed. Credit: Wyss Institute at Harvard University.
Reference: “Next-Generation Digital Information Storage in DNA” by George M. Church, Yuan Gao and Sriram Kosuri, 16 August 2012, Science.