New, Inexpensive Test Detects SARS-CoV-2 Genome Without PCR

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A new COVID-19 diagnostic test developed by researchers at the University of Washington (UW) can detect genetic material from the SARS-CoV-2 virus like PCR-based tests do but, unlike a PCR diagnostic, it can deliver results in as little as 20 minutes.

“We designed the test to be low-cost and simple enough that it could be used anywhere,” said Barry Lutz, a UW associate professor of bioengineering and investigator with the Brotman Baty Institute for Precision Medicine. “We hope that the low cost will make high-performance testing more accessible locally and around the world.”

The researchers developed the diagnostics, called the Harmony COVID-19 test, to be easy to use and to employ ready-to-use reagents. The team notes that the test is “PCR-like” and uses samples collected via a nasal swab with a low-cost detector that was also designed by the research group. The detector is operated by a cell-phone interface which also provides the test results. The compact detector can analyze up to four samples at a time and is small enough to fit into the glove compartment of a car.

The investigators published their results in a Science Advances. Initial results show that the test was 97% accurate when samples were collected via nasal swabs. This compares with inexpensive over-the-counter antigen tests which detect pieces of the protein the virus creates—not genetic material—which are 85% accurate; and PCR tests which are typically 95% accurate or better—the FDA benchmark—but require expensive equipment and a long wait time until return of results. In short, the new test returns results as quickly and cheaply as antigen testing, but with accuracy that rivals PCR.

The Harmony test delivers quick results by eliminating the need for the dozens of instances of thermocycling used in PCR testing to detect the genetic material in a sample and instead uses a PCR-like method known as RT-LAMP which doesn’t have the same temperature cycling requirements. Also, as the test detects three separate regions of the SARS-CoV-2 virus, if a new variant of the virus has mutations in one of the three regions, the test can still detect the other two, meaning it can detect the new omicron variant and potentially other future variants as well.

As Harmony was in development last year, Lutz and two colleagues spun out a new company from UW called Anavasi Diagnostics. The company received an initial grant of $300,000 from the Center for Washington Entrepreneurial Research Evaluation & Commercialization Hub (WE-REACH), which provides teaching and funding tools to accelerate the development of therapeutic, device, and diagnostic products to address significant challenges in health. It subsequently received $14.9 million in grant money from the NIH to move the Harmony kit from prototype into a commercial product and to scale up test kit production.

“For a long time, the options have been either a PCR test that is expensive and typically takes a day or more to get a result, or a rapid antigen test that gives fast results and is low cost, but typically has lower accuracy than a lab PCR test,” said Lutz. “From the first day, we designed our test to be manufacturable at low cost and high volume, while delivering fast results with PCR-like performance.”

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