Portable, point-of-care COVID-19 test discerns alpha variant from
earlier strains

Date:
April 19, 2022
Source:
University of Illinois at Urbana-Champaign
Summary:
A point-of-care COVID-19 test developed by researchers can now
detect and differentiate the alpha variant of the SARS-CoV-2 virus
from earlier strains in saliva samples.



FULL STORY ==========================================================================
A point-of-care COVID-19 test developed by researchers at the University
of Illinois Urbana-Champaign can now detect and differentiate the alpha
variant of the SARS-CoV-2 virus from earlier strains in saliva samples.


==========================================================================
The new test builds on the group's previous developments, which allowed
samples to bypass the laboratory -- first using nasopharyngeal swabs,
then with saliva samples. The point-of-care amplification and testing
process, called LAMP, is more efficient than PCR because it does not
require expensive thermal cycling machines. The researchers said the
assay does not need RNA extraction and purification steps, similar to
the Illinois saliva test.

The results of the study, co-led by Rashid Bashir, a professor of bioengineering and the dean of the Grainger College of Engineering at
Illinois, mechanical science and engineering professor Bill King and bioengineering professor Enrique Valera, are published in the journalLab
on a Chip.

"Our study shows that it is possible to test for variants of the
same coronavirus strain in a single point-of-care test that takes 30
minutes using a portable handheld device," Bashir said. "The new test
is scalable to suit future pandemics, COVID-19 or otherwise, and could
be used at home or other settings." The updated process takes advantage
of a genetic phenomenon called S-gene target failure -- which is present
in the alpha variant but not in the SARS- CoV-2 virus early strains --
to differentiate between the two alpha variants, the researchers said.

"The new omicron variant also exhibits S-gene target failure and could be tested for by adapting the approach developed in this study," Valera said.



========================================================================== During the new testing process, specially selected genetic primers are
placed onto additively manufactured cartridges and dried before adding the patient samples. The chosen primers are set against the S-gene and are
specific for detecting the S-gene target failure against 69-70 deletion
in the alpha variant, the study reports.

The study confirmed the device's effectiveness by testing 38 clinical
saliva samples, including 20 samples positive for alpha variant.

The researchers said they would like to refine their method to test up
to five different viruses, viral strains and variants in a single test, compatible with nasal swab and saliva mediums.

Co-authors of the paper were graduate students Jongwon Lim and Robert
Stavins, and Karen White and James Kumar from Carle Foundation Hospital.

The Foxconn Interconnect Technology-sponsored Center for Networked
Intelligent Components and Environments at the University of Illinois
Urbana- Champaign, the National Science Foundation and the National
Institutes of Health supported this study. Clinical samples were obtained
from Carle Foundation Hospital and the U. of I. COVID-19 detect study.

The authors are also affiliated with electrical and computer engineering,
the Beckman Institute for Advanced Science and Technology, the Carle
Illinois College of Medicine, the Holonyak Micro and Nanotechnology Lab,
the Cancer Center at Illinois, the Materials Research Laboratory and
the Carl R. Woese Institute for Genomic Biology.


========================================================================== Story Source: Materials provided by
University_of_Illinois_at_Urbana-Champaign. Original written by Lois Yoksoulian. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jongwon Lim, Robert Stavins, Victoria Kindratenko, Janice Baek, Leyi
Wang, Karen White, James Kumar, Enrique Valera, William Paul King,
Rashid Bashir. Microfluidic point-of-care device for detection of
early strains and B.1.1.7 variant of SARS-CoV-2 virus. Lab on a
Chip, 2022; 22 (7): 1297 DOI: 10.1039/d2lc00021k ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220419130911.htm

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