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Detecting the SARS-CoV-2 virus in saliva: A clinical study starts

November 11, 2020 - Source : NEWS

A multidisciplinary team and their project, led by Polytechnique Montréal’s Professor Frédéric Leblond and the CHUM’s Dr. Dominique Trudel is moving into Phase II - developing a diagnostic tool using saliva samples to detect COVID-19 carriers. Over the next few months, the team will test more than 1,000 saliva samples for COVID-19’s “Raman signature.”

Frédéric Leblond et Dre Dominique Trudel. (Photo : CHUM)

Polytechnique Montréal’s Professor Frédéric Leblond (Engineering Physics), and the CHUM’s Dr. Dominique Trudel, (Pathologist), both of whom are also researchers at the CRCHUM. (Photo: CHUM)

Equipped with a straight-forward saliva test that uses Raman spectroscopy a, few minutes, and some spit, can healthy individuals be distinguished from those with COVID-19? For the moment, this question remains unanswered. Yet according to Polytechnique Montréal’s Professor Frédéric Leblond from the Department of Engineering Physics the answer to that riddle should be known within a few months.

In collaboration with pathologist Dr. Dominique Trudel from the Centre hospitalier de l’Université de Montréal (CHUM), a research team at the CHUM Research Centre is now beginning Phase II of a project that is likely to lead to the creation of a portable COVID-19 detection tool. If all goes as planned, this tool will be used to detect the disease in individuals in about two minutes - notably without the use of biochemical reagents. Phase II of the research project is supported by the Canada Foundation for Innovation (CFI), the TransMedTech Institute, and the Natural Sciences and Engineering Research Council of Canada (NSERC).

Led by Professor Leblond and Dr. Trudel, as of last week the research team began working with a hospital that is collecting saliva samples from patients who have come for a COVID-19 screening test. Eventually, 1,000 to 1,500 samples will be collected from individuals who have had positive or negative COVID-19 tests. Samples will be dried on slides and examined under a microscope using laser light; a camera will then analyze the sample using Raman spectroscopy.

“We’re betting that we’ll be able to detect the virus and/or the systemic effects of COVID-19 in saliva samples – and we’ll use machine learning to ensure we get very reliable results,” Professor Leblond explains.

Last May marked the announcement of the start of this project, and since then the team has developed a series of protocols to collect and handle samples, with financial support from the TransMedTech Institute, the Institute for Data Valorization (IVADO), and NSERC.

In collaboration with Professors Ludvik Martinu, Jolanta-Ewa Sapieha, and Michel Meunier (all from the Department of Engineering Physics), the research team has also begun to develop new test surfaces and nanoparticles which will be used to analyze saliva samples with minimal “background noise” (ie test surfaces will permit a clearer detection of Raman signatures). The team also exploring new ways to increase the specificity of said Raman signals when detecting COVID-19 infections.

Long-term benefits

Medical benefits from this project are expected to also come in both the medium and long terms.

As was recently announced, the team has obtained financial support of close to $550,000 from the CFI and Government of Québec to create a laboratory to analyze biofluids using Raman spectroscopy.

Highly sensitive microscopes, lasers, and cameras, as well as other laboratory instruments acquired using this funding will first be used in Phase II of the COVID-19 project. Then, these same tools will be put to use developing new diagnostic tools for biofluid analysis using Raman spectroscopy, but for tests using blood and urine for example.

As an example of a related project, Professor Leblond notes a project he’s involved with in collaboration with researchers from the Montréal Neurological Institute and Hospital (the Neuro) and Centre hospitalier universitaire Sainte-Justine, wherein blood samples taken before and after brain surgery will be compared in order to determine the remission status of a patient suffering from brain cancer.

“If it works, this approach would replace the need to use medical imaging with these cancer patients,” note Leblond.

Other projects involving CRCHUM researchers are also under way, assures Professor Leblond.

 

The principles of Raman spectroscopy imaging

Our eye perceives objects because it detects the rays of light they emit. The Raman spectroscopic approach used by Professor Leblond works in the same way, with one difference: it detects rays of light whose wavelength has changed when it strikes an object.

Each substance modifies the light that is projected onto it, generating a true “molecular signature” specific to the illuminated substance. The Polytechnique Montréal and CRCHUM team is anticipating that the saliva of individuals with COVID-19 has a signature distinct from that of healthy patients, whether because of the presence of viral particles, or molecules produced by the body in response to the viral attack.


Learn more

Professor Frédéric Leblond’s expertise
Department of Engineering Physics website
CRCHUM website
TransMedTech Institute website
CFI website
NSERC website

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