No More False-Negatives: An Ultrasensitive COVID Test

A team of researchers has improved upon the current diagnostic methodology for COVID-19, making it significantly more accurate and reliable. The new cost-effective test that builds upon the commonly-used Reverse Transcription Polymerase Chain Reaction or RT-PCR protocol incorporates state-of-the-art microfluidic technology. Scientists have shown that this technique is capable of detecting even trace amounts of viral genetic material, thus significantly diminishing the risk of false-negative results.

The accuracy of COVID-19 diagnostics, or lack thereof, has been an ongoing issue since the emergence of the disease almost a year ago. These tests can be wrong in one of two ways: either a false positive or a false negative. False positives (where a person is wrongly classed as being infected) lead to unnecessary quarantining and stress for the patient. False negatives, however, are far more concerning. In these cases, asymptomatic individuals harboring the virus can continue to unwittingly infect others in the course of their daily lives, lulled into a false sense of security as a result of the negative result.

The new and improved ultrasensitive diagnostic system, created by scientists at NYU Abu Dhabi's Biology Program and Center for Genomics and Systems Biology (CGSB), uses three sequential steps to boost the test’s accuracy: RT and cDNA preamplification followed by qPCR. This enables extremely minute amounts of viral RNA present in nasal swabs and saliva samples from getting detected, slashing false-negative rates. The work detailing the development of this microfluidic-based test was presented in the journal Processes.

"By adding a pre-amplification step and using microfluidic technology, we have demonstrated that this sensitive detection method can detect low viral loads, which is critical to enabling the most effective public health responses to the COVID-19 pandemic," said Youssef Idaghdour, a researcher who led the study. 

"Our three-step approach can significantly reduce the false-negative rate of standard RT-PCR-based diagnostic tests for SARS-CoV2 and other viral infections. This would allow public health officials to more readily identify and trace asymptomatic individuals, enhance the accuracy of air and environmental sampling for SARS-CoV-2, expand accurate detection to saliva testing and help curtail the spread of the virus."

Sources: Eurekalert, Processes.