Researchers at the Federal University of São Carlos (UFSCar) have patented a new test for detecting Sars-CoV-2 in saliva. The device combines precision equivalent to that of the RT-PCR test, low cost and the ability to analyze multiple samples at the same time. In addition to detecting the presence of the virus, the new test also indicates the viral load of the infected person.
The technology used to detect the virus involves a marker with an electrochemiluminescent property (which emits light from electrochemical reactions). Thus, in the presence of the pathogen’s genetic material, a reaction occurs that emits red light, indicating a positive result for Covid-19. The intensity of red light is proportional to the viral load present in the sample. If the device does not light, it is a sign that the virus was not detected and, therefore, the person is not infected.
Another innovation is the fact that the device can be coupled to a smartphone, allowing the sampling and testing process to be completed without the need for a specialized professional. The project was supported by FAPESP, the Coordination for the Improvement of Higher Education Personnel (Capes) and the National Council for Scientific and Technological Development (CNPq).
“The test has the advantages of being portable, being able to analyze 20 samples at the same time and being able to connect to a smartphone. All with the same sensitivity and precision as RT-PCR tests”, says Ronaldo Censi Faria to the Fapesp Agency, a researcher at UFSCar’s Center for Exact Sciences and Technology and project coordinator.
This is the third test for detection of the new coronavirus developed and patented by UFSCar’s Bioanalytical and Electroanalytical Laboratory (LaBiE). The previous two are also highly sensitive and, if produced on a large scale by partner companies, may allow for mass testing of the Brazilian population — solving one of the bottlenecks for fighting the pandemic (read more at: agencia.fapesp.br/36162) .
The first technology developed by the group involved an electrochemical sensor that allows for a quantitative analysis of the spike protein (spike) of the virus in the patient’s saliva. In it, an electrochemical sensor captures the viral molecule and the result can be accessed, in a matter of minutes, through a cell phone application.
The second test model developed at LaBiE detects the RNA of the virus present in saliva. However, unlike the most recent device, it is based on an adaptation of the ELISA (enzyme-linked immunosorbent assay) platform, widely used in clinical analysis laboratories throughout Brazil.
Faria explains that the first two tests are in an advanced negotiation process with partner companies. The objective is to produce them on a large scale and market them.
“The greater the range of low-cost tests capable of accurately detecting the new coronavirus, the better. Each model adapts to a situation: remote places, clinical analysis centers or individual use”, says Faria.
A curiosity of this latest device is that it was initially designed for the diagnosis of sepsis — systemic inflammation caused by bacteria, the main cause of death in Intensive Care Units (ICUs).
The work is the result of doctoral research by Taise Helena Oliveira Leite, under the guidance of Faria. “The research and development project for the test had already started and, when the pandemic arrived, we saw that the model could be adapted for Covid-19. We quickly changed the device that initially detected the DNA and the amount of bacteria that cause sepsis to indicate the RNA and viral load of Sars-CoV-2. This shows how constant research has to be, especially when we need to respond quickly to an emergency”, analyzes Faria.
The new technology has just had its patent application registered with the National Institute of Industrial Property (INPI), owned by Faria, Leite, Tássia Regina de Oliveira (post-doctoral student at LaBiE) and collaborators: Henrique Pott Junior (UFSCar), Ester Sabino (University of São Paulo), Fabio Eudes Leal and Erika Regina Manuli (Municipal University of São Caetano do Sul) and Matias Eliseo Melendez (Cloning Solutions company). The arrival of the test to the market now depends on companies’ interest in licensing the patent and producing the device on a large scale.