COVID-19: A Method to TestMore… and Better!

ANALYZING 30,000 SAMPLES PER DAY FOR COVID-19 : THAT IS WHAT RESEARCH TEAMS FROM THE UNIVERSITÉ DE SHERBROOKE AND THE UNIVERSITÉ DE MONTRÉAL ARE WORKING ON ATTAINING.

The research teams hope to improve the screening for COVID-19 using a technology patented, developed and manufactured in Quebec, by Phytronix.

The Luxon Ion Source® will serve as a foundation for the works of Pr. Pedro Segura, of the Department of Chemistry (Université de Sherbrooke), and Pr. Francis Beaudry, of the Faculty of Veterinary Medicine (Université de Montréal). This instrument, when coupled with a mass spectrometer, allows the analysis of molecules in seconds.

With the Luxon Ion Source®, it is possible, among other things, to quantify low concentrations of contaminants in food and the environment as well as drugs in plasma and even in hair. However, the rapid screening for COVID-19 presents significant challenges for this technology: it cannot detect the presence of the virus due to the large size of the molecules that compose it (mainly proteins and genetic material). It will therefore be necessary to cut the virus into smaller parts to identify it.

The “Spike” Protein: Like a skewer impossible to swallow

In order to detect COVID-19, the team decided to focus on the protein that forms spikes at the tip of the coronavirus “crown”. This protein is essential for the virus to enter and infect human cells. While the Luxon Ion Source® is designed to analyze small molecules, such as pesticides or drugs, the spike protein represents a huge molecular skewer with its 1,273 amino acids.

Peptides, for smaller bites

The research team will test an approach that is well established, but never tested with the Luxon Ion Source®: the analysis of peptides of the spike protein generated by trypsin. Trypsin is a protein essential for the digestion of food, found in the digestive system of many vertebrates. It is able to cut other proteins into peptides, small pieces made up of a few amino acids.

Thanks to a study in bioRxiv from April 2020 by an American team led by Benjamin C. Orsburn, the specific peptides that compose the spike protein of the COVID-19 virus have been identified. These peptides serve as a fingerprint and are used to determine whether the virus is present or absent from a sample.

Researchers from the Sherbrooke and Montreal teams will verify whether the peptides can be detected by the Luxon Ion Source. Subsequently, they will develop a rapid method of isolating the spike protein and fragmenting it into peptides using trypsin. If this method works, the Luxon Ion Source would be able to analyze some 30,000 samples of the peptides from patients in 25 hours! This method could help to significantly increase the screening capacity for COVID-19 in hospitals and other health centers.