We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Abbott Diagnostics- Hematology Division

Download Mobile App

New Lateral Flow Test is Cheaper, Easier to Use and as Reliable as PCR Test for Diagnosing SARS-CoV-2 Infection

By LabMedica International staff writers
Posted on 22 Jun 2021
Print article
Image: New Lateral Flow Test is Cheaper, Easier to Use and as Reliable as PCR Test for Diagnosing SARS-CoV-2 Infection (Photo courtesy of Alxddd000/ Shutterstock)
Image: New Lateral Flow Test is Cheaper, Easier to Use and as Reliable as PCR Test for Diagnosing SARS-CoV-2 Infection (Photo courtesy of Alxddd000/ Shutterstock)
A SARS-CoV-2 lateral flow test that combines two bacterial enzymes with genetic sequences and a couple of probes is cheaper and easier to use than PCR tests while producing comparably reliable results.

Called Vigilant and designed at King Abdullah University of Science and Technology (KAUST; Thuwal, Saudi Arabia), the test can detect very small amounts of viral RNA in a sample. PCR tests, which are conducted in laboratories, produce more reliable results but are expensive and require sophisticated equipment and skilled personnel.

The first critical step of the Vigilant platform involves a technique called reverse transcription-recombinase polymerase amplification (RT-RPA) to make many copies of a specific region on the SARS-CoV-2 genome, if it exists in a person’s nose and throat swab sample. PCR tests also amplify viral gene sequences in samples but involve putting the samples through multiple high and low temperature cycles. RT-RPA can be done at room temperature with much cheaper and easy-to-use equipment.

Any SARS-CoV-2 amplified genes in the product of this process are tagged with a molecule called biotin, then added to a test tube containing KAUST’s specially designed detection complex. This complex is formed of two enzymes. On one end, a bacterial enzyme called Cas9 is conjugated with an RNA guide that only recognizes and attaches to the corresponding SARS-CoV-2 gene sequence. On the other end, another bacterial enzyme called VirD2 is attached to a fluorescent-tagged nucleotide sequence.

Drops from the reaction between the complex and RT-RPA product are then added to a lateral flow test strip impregnated with a biotin-recognizing protein called streptavidin on one end and a fluorescent probe-recognizing antibody on the other. If the sample contains SARS-CoV-2 gene sequences, they will have bound to the VirD2-Cas9 complex. A positive result occurs when two visible lines appear. The first line is where biotin on the SARS-CoV-2 amplicon binds to streptavidin. The second line is where the fluorescent tag on the other end of the complex attaches to the strip’s antibody. A negative result shows only as a single line caused by the fluorescent tag binding to the antibody.

“Several types of lateral flow tests are currently available or under research for detecting SARS-CoV-2,” said KAUST Ph.D. student Tin Marsic. “Depending on how they work, they all have disadvantages, including detecting the virus only several days after infection or producing false positive and false negative results. Vigilant can be conducted in non-laboratory settings and is significantly cheaper and easier to use than PCR tests.”

“We’re now working on making our Vigilant platform more user-friendly by coupling it with an even simpler amplification technique,” added KAUST bioengineer Magdy Mahfouz, who led the research. “We are also working on producing other efficient and rapid diagnostic tests that can detect nucleic acids to enable point-of-care testing for pathogens, including viruses and disease markers.”

Related Links:

Gold Supplier
Liquid Handling Workstation
AdvanSure E3 SYSTEM
Clinical Chemistry Analyzer
Mispa CXL Pro
Methicillin-Resistant Staphylococcus Aureus RT PCR Test
VIASURE Methicillin-Resistant Staphylococcus Aureus Real Time PCR Detection Kit
Gold Supplier
Fluorimetric Immunoassay Analyzer
Confiscope F20

Print article



view channel
Image: The CellSearch Circulating Tumor Cell Kit is intended for the enumeration of circulating tumor cells of epithelial origin (CD45-, EpCAM+, and cytokeratins 8, 18+, and/or 19+ and PD-L1) in whole blood (Photo courtesy of CellSearch/Menarini Silicon Biosystems)

PD-L1 Expression in Circulating Tumor Cells Investigated for NSCLC

In non-small cell lung cancer (NSCLC), analysis of programmed cell death ligand 1 (PD-L1) expression in circulating tumor cells (CTCs) is a potential alternative to overcome the problems linked to the... Read more


view channel

Global Digital Polymerase Chain Reaction (dPCR) Market Projected to Reach Close to USD 1.15 Billion by 2028

The global digital polymerase chain reaction (dPCR) market is projected to grow at a CAGR of more than 9% from over USD 0.50 billion in 2020 to nearly USD 1.15 billion by 2028, driven primarily by rising... Read more
Copyright © 2000-2021 Globetech Media. All rights reserved.