Tiny nets woven from DNA strands cover the spike proteins of the virus that causes COVID-19 and give off a glowing signal in this artist’s rendering. Credit: Xing Wang, University of Illinois
Key Points:
- Researchers have developed tiny nets woven from DNA strands that can catch the spike protein of SARS-CoV-2, lighting up the virus to act as a diagnostic test.
- In a study, the nets showed sensitivity on-par with PCR tests, today’s gold standard.
- The nets are a low-cost option for rapid testing.
Researchers at the University of Illinois Urbana-Champaign have designed tiny nets woven from DNA strands that can capture the spike protein of SARS-CoV-2. Once bound, nets give off a fluorescent signal that can be read by an inexpensive handheld device in about 10 minutes, making for a fast and sensitive diagnostic test.
In their study published in the Journal of the American Chemical Society, the researchers demonstrated that their DNA nets were able to detect the virus at levels equivalent to the sensitivity of gold-standard PCR tests that can take a day or more to return results from a clinical lab.
“Another advantage of this measure is that we can detect the entire virus, which is still infectious, and distinguish it from fragments that may not be infectious anymore,” said study leader Xing Wang, a professor of bioengineering and chemistry at Illinois.
This would not only give patients and physicians better understanding of whether they are infectious, but it could also greatly improve community-level modeling and tracking of active outbreaks.
In addition, the DNA nets inhibited the virus’s spread in live cell cultures, with the antiviral activity increasing with the size of the DNA net scaffold. The researchers say this points to DNA structures’ potential as therapeutic agents.
“I had this idea at the very beginning of the pandemic to build a platform for testing, but also for inhibition at the same time,” said Wang. “Lots of other groups working on inhibitors are trying to wrap up the entire virus, or the parts of the virus that provide access to antibodies. This is not good, because you want the body to form antibodies. With the hollow DNA net structures, antibodies can still access the virus.”
The DNA net is flexible—is can be adapted to other viruses, and even multiplexed so a single test could detect multiple viruses.
“We're trying to develop a unified technology that can be used as a plug-and-play platform. We want to take advantage of DNA sensors’ high binding affinity, low limit of detection, low cost and rapid preparation,” Wang said.
The researchers estimate that the method would cost $1.26 per test.
Information provided by University of Illinois Urbana-Champaign.