In a new study, researchers have developed a rapid, portable, saliva-based COVID-19 test able to return results in 45 minutes. Such a test might eventually be deployable in community settings like schools and factories.
The research was conducted by CU Boulder scientists.
Scientists are facing a serious testing shortage in the U.S. right now as more people want to get tested and diagnostics labs are overwhelmed.
The test is designed for widespread screening to help identify asymptomatic people.
Research shows people infected with the virus but with no obvious symptoms make up as many as 70% of cases and can still spread disease.
In this new test, a user spits in a tube, adds a solution to stabilize it then closes the lid and hands it off to testing staff.
They process it through a simple system requiring little more than pipettes, a heating source and an enzyme mixture.
If the sample turns from pink to yellow, the test is positive. If it doesn’t, it’s negative.
Because no swabs are required, and no fancy equipment is needed, the tests are less vulnerable to backlogs and supply chain shortages, the researchers say.
The test is based on a 20-year-old technology known as reverse transcription loop-mediated isothermal amplification (RT-LAMP) previously used, for instance, to screen mosquitoes for the Zika virus in remote regions of South America.
Once a sample is collected, it is heated to liberate any viral genome present in the test liquid.
This sample is then added to three tubes, each containing a custom enzyme mixture which, when heated to a certain temperature, undergoes a chemical reaction when the genetic material from SARS-CoV-2 is detected. That’s the virus that causes COVID-19.
The team found the test predicted with 100% accuracy all of the negative samples, and 29 of 30 positive samples were predicted accurately. They noted that the 30th test was scored as inconclusive.
Additional second-party validation tests are currently underway.
The authors note that the test is slightly less sensitive than those performed in clinical labs.
But a separate computer modeling study found that quick turnaround for testing is even more critical to curbing the pandemic than test sensitivity is.
One author of the study is Nicholas Meyerson, a postdoctoral associate in the Sawyer Lab at the BioFrontiers Institute at CU Boulder.
The study is published in MedRxiv.org.
Copyright © 2020 Knowridge Science Report. All rights reserved.
