The genetic material DNA has garnered considerable interest as a medium for digital information storage because its density and durability are superior to those of existing silicon-based storage media. For example, DNA is at least 1000-fold more dense than the most compact solid-state hard drive and at least 300-fold more durable than the most stable magnetic tapes. In addition, DNA’s four-letter nucleotide code offers a suitable coding environment that can be leveraged like the binary digital code used by computers and other electronic devices to represent any letter, digit, or other character.
Despite these advantages, DNA has not yet become a widespread information storage medium because the cost of chemically synthesizing DNA is still prohibitively high at $3,500 per 1 megabyte of information. To help overcome this limitation, research at the Wyss Institute spearheaded by Henry Hung-Yi Lee, Ph.D., in a collaborative project led by Core Faculty member George Church, Ph.D., and Founding Director Donald Ingber, M.D., Ph.D., has developed new, enzyme-based approaches that can write DNA simpler and faster than traditional chemical techniques. These approaches could also produce much longer strands of DNA while being less toxic for the environment. Importantly, this approach is projected to reduce the cost of DNA synthesis in the future by many orders of magnitude.
To scale up their approach, the team is developing an integrated DNA information storage device in which programmable enzymatic DNA synthesis can be achieved in a highly multiplexed fashion. In biology and in vitro biochemistry methods, a new strand of DNA is synthesized by copying an already existing template strand with enzymes known as DNA polymerases. For synthesizing DNA de novo, however, the Wyss Institute’s approach deploys a template-independent DNA polymerase and controls its activity — which of the four nucleotide-letters to add at each step of DNA strand synthesis — electronically. At scale, this storage device will yield a highly parallelized synthesis process suitable for storing the exponentially growing amount of digital information in DNA.