New approach to DNA data storage makes system more dynamic, scalable

June 12, 2020

Researchers from North Carolina State University 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 Albert Keung, co-corresponding author of a paper on the work. "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." Keung is an assistant professor of chemical and biomolecular engineering at NC State.

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.

"In other words, DORIS can work at room temperature, making it much more feasible to develop DNA data management technologies that are viable in real-world scenarios," says James Tuck, co-corresponding author of the paper and a professor of electrical and computer engineering at NC State.

The other benefit of not having to rip apart the DNA strands is that the DNA sequence in the overhang can be the same as a sequence found in the double-stranded region of the data file itself. That's difficult to achieve in PCR-based systems without sacrificing information density - because the system wouldn't be able to differentiate between primer-binding sequences and data-storage sequences.

"DORIS allows us to significantly increase the information density of the system, and also makes it easier to scale up to handle really large databases," says Kevin Lin, first author of the paper and a Ph.D. student at NC State.

And once DORIS has identified the correct DNA sequence, it doesn't rely on PCR to make copies. Instead, DORIS transcribes the DNA to RNA, which is then reverse-transcribed back into DNA which the data-storage system can read. In other words, DORIS doesn't have to consume the original file in order to read it.

The single-stranded overhangs can also be modified, allowing users to rename files, delete files or "lock" them - effectively making them invisible to other users.

"We've developed a functional prototype of DORIS, so we know it works," Keung says. "We're now interested in scaling it up, speeding it up and putting it into a device that automates the process - making it user friendly."
The paper, "Dynamic and scalable DNA-based information storage," will be published June 12 in the journal Nature Communications. The paper was co-authored by Kevin Volkel, a Ph.D. student at NC State.

The work was done with support from the National Science Foundation, under grants CNS-1650148 and CNS-1901324; a North Carolina State University Research and Innovation Seed Funding Award; a North Carolina Biotechnology Center Flash Grant; and a Department of Education Graduate Assistance in Areas of Need fellowship.

North Carolina State University

Related DNA Articles from Brightsurf:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.

Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.

Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.

Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.

Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.

DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.

A new spin on DNA
For decades, researchers have chased ways to study biological machines.

From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.

Read More: DNA News and DNA Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to