The test distinguishes SARS-CoV-2 from other coronaviruses with 100% accuracy


This point-of-care device uses fluid physics to extract a few drops of blood and biomedical lubricant through its components to test antibodies and biomarkers COVID-19 without the need for electricity. Credit: Jake Heggestad

Duke University biomedical engineers have demonstrated a tablet-sized device that can reliably detect multiple COVID-19 antibodies and biomarkers simultaneously.

The initial results show the can distinguish between antibodies produced in response to SARS-CoV-2 and four other coronaviruses with 100% accuracy.

Researchers are now working to see if the easy-to-use, energy-independent point-of-care device can be used to predict the severity of a COVID-19 infection or a person’s immunity to variants. of the virus.

Researchers say the results show the flexibility of the technology to adapt to other current or future diseases, as it has recently been shown that the same “D4 trial” platform can detect Ebola infections a day before the reaction test in standard polymerase chain (PCR). .

The results appear online June 25 a Scientific advances.

“The D4 trial took six years to develop, but when the WHO declared the outbreak a pandemic, we started working to compress all this work in a few months so we could explore how the test could be used as a pandemic. public health tool “. said Ashutosh Chilkoti, Distinguished Professor Alan L. Kaganov and Professor of Biomedical Engineering at Duke. “Our test is designed to be adaptable and really a point of care, and this is clearly a scenario where a portable, fast and cost-effective diagnosis would be more useful.”

The technology is based on a polymer brush coating that acts as a kind of non-stick coating to prevent anything but the desired biomarkers from adhering to the test slide when wet. The high efficiency of this non-stick shield makes the D4 test incredibly sensitive even at low levels of its targets. The approach allows researchers to print different molecular traps in different areas of the slide to capture multiple biomarkers at once.

The current iteration of the platform also includes tiny patterned tunnels that use liquid physics to extract samples through the channels without the need for electricity. With just one drop of blood and one drop of biomolecular lubricant, the test is done autonomously in a matter of minutes and can be read with a detector about the size of a very thick iPad.

The test distinguishes SARS-CoV-2 from other coronaviruses with 100% accuracy

The D4 analysis is read by this battery-powered tablet-sized device, which allows you to throw the set into your backpack and use it at the point of attention with the least resources. Credit: Jake Heggestad

“The detector runs on battery power and the test doesn’t require any power supply, so you can throw it all in your backpack and really test it to the point of attention with minimal resources,” said Jason Liu, a doctor. D. student working in the Chilkoti lab who designed and built the detector.

In the current study, the researchers tested the ability of the D4 assay to detect and quantify antibodies produced against three parts of the COVID-19 virus: a subunit of the ear protein, a binding domain within the ear protein that it adheres to the cells and nucleocapsid protein that packs the virus’s RNA. The test was able to detect antibodies in all 31 patients tested with severe cases of COVID-19 after two weeks. It also reported zero false positives in 41 samples taken from healthy people before the pandemic began, as well as in 18 samples taken from individuals infected with four other circulating coronaviruses.

With the pandemic on the decline in the United States and hundreds of other COVID-19 antibody tests in development, researchers do not believe that this particular test can be deployed in large numbers. But they say the platform’s proven accuracy and flexibility make it a prime candidate for developing in other types of testing or for use in future outbreaks.

For example, the platform might be able to test whether or not people have immunity to the different COVID-19 strains that continue to emerge.

“There are a lot of questions from people about whether or not they are protected from new variants of COVID-19, and our test could answer some of those,” said Jake Heggestad, a Ph.D. student working in the Chilkoti lab who developed the chip for the test. “We believe our platform should be able to distinguish whether people have antibodies that can neutralize emerging variants of concern or whether those antibodies will not be protective against new variants.”

Researchers are also working to develop the platform in a test of multiple prognostic markers of COVID-19 that together can indicate whether or not a patient is likely to have a severe case of the disease.

“We’re platform builders, so we work to show ways this technology can be easily modified to do different things,” said David Kinnamon, a graduate student who developed the liquid handling system for the test. “We’re showing that this unique platform can function as a diagnosis, assess the immune response after infection, and predict the outcome of the disease, potentially at the same time. I don’t know many tests that can do that.”

“And you can do all of this on a platform that’s easy to use and transportable,” Heggestad said. “It’s one thing to do all this in a centralized facility like Duke, but it’s another to be able to do large-scale testing and get good sensitive results in remote locations around the world.”

Biomedical engineers adapt the rapid testing platform to see if it can capture COVID-19

More information:
JT Heggestad et al., “Multiplexed quantitative serological profile of COVID-19 from blood using a cure point test.” Scientific advances (2021).… .1126 / sciadv.abg4901

Citation: The test distinguishes SARS-CoV-2 from other coronaviruses with 100% accuracy (2021, June 25) retrieved June 25, 2021 from sars-cov-coronaviruses-accuracy. html

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