Angew. Chem. Int. Ed. http://doi.org/f3qqgw (2016)
Rapid advances in DNA nanotechnology, along with the high data density and longevity of DNA, suggest that DNA computing may soon be more than a proof-of-concept technology.
Inspired by the biological regulation of epigenetic information (heritable changes in gene expression), Shankar Balasubramanian and colleagues at the University of Cambridge now show that a single DNA template can store multiple layers of binary data. The bisulfite-catalysed conversion of cytosine (C) to uracil (U) forms the basis of a two-layer binary encoding system. C positions that encode for 0 are turned to 1, and G positions that encode for 1 are transformed to 0. As the adenine and thymine positions are unaffected, the designed sequence gives different readouts before and after chemical treatment. This was demonstrated by the concurrent storage of the first two stanzas of The Raven by Edgar Allan Poe in a DNA sequence.
A three-layer encoding system was also achieved by introducing 5-hydroxymethylcytosine residues, which convert to U after KRuO4 oxidation and bisulfite treatment. This allows the simultaneous encoding of the images of Rosalind Franklin, Charles Darwin and Alan Turing in a single piece of DNA. Chemical reduction can then be used to reversibly reveal any of the three images.