Novel test method detects COVID-19 virus in highly diluted gargle samples

London: Using mass spectrometry on gargle solutions of COVID-19 patients, German researchers have succeeded in detecting small amounts of the novel coronavirus.

The novel method is currently undergoing improvements and might be available as a standard diagnostic tool for COVID-19 in the future, the study, published in the Journal of Proteome Research, reported.

“Although we received only a small amount of gargle solution, we were able to detect components of viral proteins,” said study researcher Christian Ihling from the Martin Luther University Halle-Wittenberg (MLU) in Germany.

According to the researchers, the most prominent test method is used to detect whether someone suffers from an acute COVID-19 infection is the polymerase chain reaction, or briefly, PCR.

The PCR technique is highly specific as it detects the viral genome. Alternative tests detect antibodies against the disease.

As antibodies are generated in the body during the course of the infection, they can only be used to detect a past infection or an advanced stage of the disease.

Antibody tests are often non-specific and sometimes unable to distinguish between the different coronaviruses that can affect humans. Testing labs worldwide are therefore reaching the limits of their capabilities.

Professor Andrea Sinz, a mass spectrometry expert at the Institute of Pharmacy at MLU, had the idea of developing a new mass spectrometry-based test to complement PCR.

Mass spectrometry allows molecules to be precisely identified based on their mass and charge. The research team developed a method to look for components of SARS-CoV-2 viruses.

“We directly measure the proteins of the virus, not the genetic material,” Sinz explained.

For the experiments, the research team provided gargle solutions of three COVID-19 patients. They developed a method to detect virus components in these highly diluted samples.

“This was quite surprising, and I hadn’t expected it to work myself,” Sinz said.

The test is highly specific for the virus since the corresponding proteins are only present in SARS-CoV-2. In addition, the test can be used in the early stages of the disease when many viruses are present in the mouth and throat.

According to the research team, the test currently takes about 15 minutes.

The research group is now trying to further reduce the analysis time using artificially produced virus components.