October 2, 2022

Medical Trend

Medical News and Medical Resources

Fast and Inexpensive Test Accurately Detects COVID-19 Virus Without PCR

Fast and Inexpensive Test Accurately Detects COVID-19 Virus Without PCR



Science Sub-Journal: Fast and Inexpensive Test Accurately Detects COVID-19 Virus Without PCR

In a new study, researchers from the University of Washington have developed a new COVID-19 test that combines the benefits of an over-the-counter antigen test. Speed ​​and accuracy of PCR tests performed in medical laboratories and hospitals.

The test, called Harmony COVID-19, is a diagnostic test that, like PCR tests for COVID-19, detects genetic material from the SARS-CoV-2 virus. However, while traditional PCR tests can take hours, the Harmony COVID-19 kit can provide results within 20 minutes for some samples with similar accuracy.

Related research results were recently published in the journal Science Advances with the title “Harmony COVID-19: A ready-to-use kit, low-cost detector, and smartphone app for point-of-care SARS-CoV-2 RNA detection” .

“We designed the test method to be low-cost and simple enough to use anywhere,” said senior author Barry Lutz, associate professor of bioengineering at the University of Washington. “We hope that low cost will make high-performance tests more readily available locally and around the world.” .”

The Harmony COVID-19 developed by these authors is simple and easy to use, using ready-to-use reagents. The test uses a “PCR-like” method to detect the presence of the SARS-CoV-2 RNA genome in nasal swab samples with the aid of a small, low-cost detector also designed by Lutz’s team. A smartphone was used to operate the detector and read the results. The detector can process up to four samples at a time and can fit in the glove box of a standard car.

Fast and Inexpensive Test Accurately Detects COVID-19 Virus Without PCR
Lyophilized RT-LAMP and its analytical sensitivity. Image via Science Advances, 2021, doi:10.1126/sciadv.abj1281.

The accuracy of COVID-19 testing has been a pressing issue throughout the pandemic. Many antigen kits for at-home testing for COVID-19, which detect fragments of protein produced by SARS-CoV-2 rather than its genetic material, are 80% to 85% accurate, but Omicron variants may be less accurate,  Because the Omicron variant contains relatively more mutations that other SARS-CoV-2 strains do not have.

PCR tests are often 95 percent accurate or better — a key FDA benchmark, but require expensive equipment and long waits to get results.

Preliminary results reported in this paper showed that the Harmony COVID-19 kit was 97 percent accurate on nasal swabs.

The kit can detect three distinct regions of the SARS-CoV-2 viral genome. If a new variant has many mutations in one region, the new test can still detect the other two regions.

For example, it can detect the Omicron variant, which has dozens of mutations in the region of the genome that encodes its spike protein.

Although PCR-based tests are very accurate, a key limitation is that PCR tests require dozens of cycles of heating and cooling to detect genetic material in a sample.

The test developed by Lutz’s team circumvents this problem by relying on an amplification method called RT-LAMP, which does not have the same stringent temperature cycling requirements. “This test method is performed at a constant temperature, so it eliminates heating and cooling time and gives results in about 30 minutes,” Lutz said.

Lutz and two colleagues spun out a new company from the University of Washington, Anavasi Diagnostics, which received $300,000 in support from the WE-REACH project last year and later from the National Institutes of Health. A $14.9 million grant to develop and scale up production of the Harmony COVID-19 prototype kit to help address the ongoing shortage of COVID-19 diagnostic tests.

Initially, Lutz and his team hope the kits can be used first in clinics and other medically supervised settings, such as workplaces and schools. Later, they hope to improve the test for home use.

“For a long time, people’s options have been either expensive PCR tests, which often take a day or more to get results, or rapid antigen tests, which can get results quickly and cost less, but are generally more expensive than laboratory PCR tests,” Lutz said. The accuracy is low. From day one, we designed our test to be manufactured at low cost and in high volume, while providing rapid results with PCR-like performance.”

“We plan to make our test available worldwide and at an affordable price,” Lutz said. 

Reference:

Nuttada Panpradist et al. Harmony COVID-19: A ready-to-use kit, low-cost detector, and smartphone app for point-of-care SARS-CoV-2 RNA detection. Science Advances, 2021, doi:10.1126/sciadv.abj1281.

Fast and Inexpensive Test Accurately Detects COVID-19 Virus Without PCR

(source:internet, reference only)


Disclaimer of medicaltrend.org