New approach to DNA data storage makes system more dynamic, scalable
Researchers in the College have developed a fundamentally new approach to DNA data storage systems, giving users the ability to read or modify data files without destroying them and making the systems easier to scale up for practical use.
“Most of the existing DNA data storage systems rely on polymerase chain reaction (PCR) to access stored files, which is very efficient at copying information but presents some significant challenges,” says Dr. Albert Keung, co-corresponding author of a paper on the work and an assistant professor in the Department of Chemical and Biomolecular Engineering. “We’ve developed a system called Dynamic Operations and Reusable Information Storage, or DORIS, that doesn’t rely on PCR. That has helped us address some of the key obstacles facing practical implementation of DNA data storage technologies.”
DNA data storage systems have the potential to hold orders of magnitude more information than existing systems of comparable size. However, existing technologies have struggled to address a range of concerns related to practical implementation.
Current systems rely on sequences of DNA called primer-binding sequences that are added to the ends of DNA strands that store information. In short, the primer-binding sequence of DNA serves as a file name. When you want a given file, you retrieve the strands of DNA bearing that sequence.
Many of the practical barriers to DNA data storage technologies revolve around the use of PCR to retrieve stored data. Systems that rely on PCR have to drastically raise and lower the temperature of the stored genetic material in order to rip the double-stranded DNA apart and reveal the primer-binding sequence. This results in all of the DNA — the primer-binding sequences and the data-storage sequences — swimming free in a kind of genetic soup. Existing technologies can then sort through the soup to find, retrieve and copy the relevant DNA using PCR. The temperature swings are problematic for developing practical technologies, and the PCR technique itself gradually consumes — or uses up — the original version of the file that is being retrieved.
DORIS takes a different approach. Instead of using double-stranded DNA as a primer-binding sequence, DORIS uses an “overhang” that consists of a single-strand of DNA — like a tail that streams behind the double-stranded DNA that actually stores data. While traditional techniques required temperature fluctuations to rip open the DNA in order to find the relevant primer-binding sequences, using a single-stranded overhang means that DORIS can find the appropriate primer-binding sequences without disturbing the double-stranded DNA.
Kevin Lin and Kevin Volkel, both Ph.D. students at NC State, are first author and co-author, respectively, of the paper.
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