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

Download Mobile App





Virus-Like Probes Could Help Make Rapid COVID-19 Testing More Accurate and Reliable

By HospiMedica International staff writers
Posted on 02 Dec 2020
Print article
Image: Illustration and TEM image of SARS-CoV-2 positive control made from plant virus-based nanoparticles (left) and bacteriophage nanoparticles (right) (Photo courtesy of Soo Khim Chan/ACS Nano)
Image: Illustration and TEM image of SARS-CoV-2 positive control made from plant virus-based nanoparticles (left) and bacteriophage nanoparticles (right) (Photo courtesy of Soo Khim Chan/ACS Nano)
A team of nanoengineers has developed new and improved probes, known as positive controls, that could make it easier to validate rapid, point-of-care diagnostic tests for COVID-19 across the globe.

The positive controls, made from virus-like particles by nanoengineers at the University of California San Diego (La Jolla, CA, USA), are stable and easy to manufacture. Researchers say the controls have the potential to improve the accuracy of new COVID-19 tests that are simpler, faster and cheaper, making it possible to expand testing outside the lab.

Positive controls are a staple in the lab - they are used to verify that a test or experiment indeed works. The positive controls that are primarily used to validate today’s COVID-19 tests are naked synthetic RNAs, plasmids or RNA samples from infected patients. But the issue is RNA and plasmids are not stable like viral particles. They can degrade easily and require refrigeration, making them inconvenient and costly to ship around the world or store for long periods of time.

By packaging segments of RNA from the SARS-CoV-2 virus into virus-like particles, the researchers have shown that they can create positive controls for COVID-19 tests that are stable - they can be stored for a week at temperatures up to 40 C (104 F), and retain 70% of their activity even after one month of storage - and can pass detection as the novel coronavirus without being infectious. The team developed two different controls: one made from plant virus nanoparticles, the other from bacteriophage nanoparticles. The controls are run and analyzed right alongside a patient sample, providing a reliable benchmark for what a positive test result should look like.

To make the plant virus-based controls, the researchers use the cowpea chlorotic mottle virus, which infects black-eyed pea plants. They essentially open the virus, remove its RNA contents, replace them with a synthesized RNA template containing specific sequences from the SARS-CoV-2 virus, then close everything back up. The process to make the bacteriophage-based controls starts with plasmids, which are rings of DNA. Inserted into these plasmids are the gene sequences of interest from the SARS-CoV-2 virus, as well as genes coding for surface proteins of the bacteriophage Qbeta. These plasmids are then taken up by bacteria. This process reprograms the bacteria to produce virus-like particles with SARS-CoV-2 RNA sequences on the inside and Qbeta bacteriophage proteins on the outside.

Both controls were validated with clinical samples. A big advantage, the researchers point out, is that unlike the positive controls used today, these can be used in all steps of a COVID-19 test. So far, the researchers have adapted their controls for use in the CDC-authorized RT-PCR test. While this is currently the gold standard for COVID-19 testing, it is expensive, complex, and can take days to return results due to the logistics of sending samples off to a lab with PCR capability. The researchers are now working on adapting the controls for use in less complex diagnostic tests like the RT-LAMP test that can be done on the spot, out of the lab and provide results right away.

“Our goal is to make an impact not necessarily in the hospital, where you have state-of-the-art facilities, but in low-resource, underserved areas that may not have the sophisticated infrastructure or trained personnel,” said Nicole Steinmetz, a professor of nanoengineering at the UC San Diego Jacobs School of Engineering. “It’s a relatively simple nanotechnology approach to make low-tech assays more accurate. This could help break down some of the barriers to mass testing of underserved populations in the U.S. and across the world.”

Related Links:
University of California San Diego

Gold Member
Real-Time Diagnostics Onscreen Viewer
GEMweb Live
Gold Member
Solid State Kv/Dose Multi-Sensor
AGMS-DM+
Silver Member
Wireless Mobile ECG Recorder
NR-1207-3/NR-1207-E
New
Forceps
BiClamp LAP

Print article

Channels

Critical Care

view channel
Image: The permeable wearable electronics developed for long-term biosignal monitoring (Photo courtesy of CityUHK)

Super Permeable Wearable Electronics Enable Long-Term Biosignal Monitoring

Wearable electronics have become integral to enhancing health and fitness by offering continuous tracking of physiological signals over extended periods. This monitoring is crucial for understanding an... Read more

Surgical Techniques

view channel
Image: NTT and Olympus have begun the world\'s first joint demonstration experiment of a cloud endoscopy system (Photo courtesy of Olympus)

Cloud Endoscopy System Enables Real-Time Image Processing on the Cloud

Endoscopes, which are flexible tubes inserted into the body's natural openings for internal examination and biopsy collection, are becoming increasingly vital in medical diagnostics. Their minimal invasiveness... Read more

Patient Care

view channel
Image: The newly-launched solution can transform operating room scheduling and boost utilization rates (Photo courtesy of Fujitsu)

Surgical Capacity Optimization Solution Helps Hospitals Boost OR Utilization

An innovative solution has the capability to transform surgical capacity utilization by targeting the root cause of surgical block time inefficiencies. Fujitsu Limited’s (Tokyo, Japan) Surgical Capacity... Read more

Health IT

view channel
Image: First ever institution-specific model provides significant performance advantage over current population-derived models (Photo courtesy of Mount Sinai)

Machine Learning Model Improves Mortality Risk Prediction for Cardiac Surgery Patients

Machine learning algorithms have been deployed to create predictive models in various medical fields, with some demonstrating improved outcomes compared to their standard-of-care counterparts.... Read more

Point of Care

view channel
Image: The PATHFAST hs-cTnI-II high-sensitivity troponin assay has been developed for the PATHFAST Biomarker Analyzer (Photo courtesy of Polymedco)

POC Myocardial Infarction Test Delivers Results in 17 Minutes

Chest pain is the second leading cause of emergency department (ED) visits by adults in the United States, generating over 7 million visits annually. In the event of a suspected heart attack, physicians... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.