APR 16, 2020 9:38 AM PDT

A New Way to Quickly Test for COVID-19

WRITTEN BY: Carmen Leitch

PCR (polymerase chain reaction) is a fundamental tool used in many aspects of biological research. In the reaction, a specific piece of DNA can be identified and amplified using short strands of nucleotides called primers. These primers can amplify DNA of interest from very small quantities of template DNA in a sample. For example, a patient's blood can be tested for COVID-19 by using primers that are specific to the genetic material of SARS-CoV-2. If the virus is present, the primers will find it and will amplify it so it can be detected.

Identifying people who have the virus and testing their contacts will be the fastest way to get society functioning again. Unfortunately, however, huge numbers of these PCR-based tests would be needed to do that, and this massive demand may overwhelm the supply of PCR reagents. These tests can also be unreliable; there have been reports of false-positive and false-negative results.

To ease the strain on PCR reagents and the machines that are used to carry out the reactions, scientists have been looking for other ways to diagnose the virus, including CT scans and antibody tests. Researchers have now created a diagnostic test based on a concept called plasmonic photothermal sensing. The work has been reported in ACS Nano.

In this method (explained in the video), a beam of light hits a metallic surface, and that beam then bounces onto a detector. The metallic surface is a sensor chip, and the electrons inside get excited by the light beam hitting the surface; they resonate. In this case, the sensor chip holds probes that recognize sequences of SARS-CoV-2 RNA. These probes are linked to gold nanoparticles. When pieces of the viral genome are present in a sample, the viral RNA will link up with the probes, and by applying heat, false-positives are reduced.

When the researchers tested their method, the assay was very specific; it was able to tell the difference between SARS-CoV-2 and a close viral relative, SARS-CoV-1. One drawback of the diagnostic test, however, is that it requires intact viral RNA from patient samples.

Colorized scanning electron micrograph of an apoptotic cell (green) heavily infected with SARS-COV-2 virus particles (purple), isolated from a patient sample. Image captured and color-enhanced at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. / Credit: NIAID

Sources: AAAS/Eurekalert! via American Chemical Society, ACS Nano

About the Author
Bachelor's (BA/BS/Other)
Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
OCT 18, 2022
Genetics & Genomics
Mitochondrial DNA Can Move to the Genome to Trigger Human Evolution
Mitochondrial DNA Can Move to the Genome to Trigger Human Evolution
Mitochondria are often called the powerhouse of the cell, and these organelles are well-known for their energy-generatin ...
NOV 30, 2022
Immunology
Rogue, Cancer-Linked Immune Cells Found to Drive Autoimmune Disorders
Rogue, Cancer-Linked Immune Cells Found to Drive Autoimmune Disorders
Leukemia patients are more likely to get autoimmune disorders like aplastic anemia or rheumatoid arthritis than unaffect ...
DEC 08, 2022
Genetics & Genomics
The Oldest Known DNA, From Many Organisms, is Discovered & Described
The Oldest Known DNA, From Many Organisms, is Discovered & Described
For the first time, scientists have recovered sediment containing 2-million-year-old DNA, shattering the previous 'oldes ...
JAN 10, 2023
Health & Medicine
Liver Let Die: Dying Liver Cells Disclose Cancer Diagnosis
Liver Let Die: Dying Liver Cells Disclose Cancer Diagnosis
The methylation patterns of DNA in the blood offer insight into the liver disease stage
JAN 12, 2023
Cancer
Can Abnormalities in Blood Cells Lead to Lung Cancer?
Can Abnormalities in Blood Cells Lead to Lung Cancer?
Hematopoiesis, a biological process resulting in the formation of new blood cells, occurs throughout our lifetime.  ...
JAN 14, 2023
Neuroscience
Social Support May Offset Genetic Risk for Depression
Social Support May Offset Genetic Risk for Depression
Social support may offset depression among those genetically predisposed to the condition. The corresponding study was p ...
Loading Comments...