Digital RT-PCR Chip method for detection of SARS-CoV-2 virus.

The "gold standard" method for detection of SARS-CoV-2 is the real time reverse transcription-polymerase chain reaction, but due to pre-analytical and technical limitations, biological samples with low viral load are not sometimes detected. For this purpose a digital RT-PCR method on-chip was developed for detection of the SARS-CoV-2 virus, using two TaqMan™ Assays for quantification of the N Protein (Nucleocapsid) and the S Protein (Spike), and the QuantStudio™ 3D Digital PCR instrument. The method was applied to assess the nasopharyngeal swabs of asymptomatic subjects recruited in the UNICORN Study. The digital RT-PCR method is characterized by a higher sensitivity than the RT-qPCR method, even if performed with the same TaqMan™, and could be a promising tool for SARS-CoV-2 viral load quantification.