Highly sensitive detection of SARS-CoV-2 by Crystal Digital PCR™

The current gold standard for COVID-19 diagnosis is based on the detection of SARS-CoV-2 nucleic acid using real-time quantitative PCR (RT-qPCR). Recent studies suggest limitations of RT-qPCR in the detection of SARS-CoV-2, possibly leading to false-negative results. Development of robust and sensitive laboratory tests is of primary importance. Digital PCR is a promising approach to address this challenge, in particular the Crystal Digital™ PCR workflow from Stilla Technologies. To confirm this hypothesis, a SARS-CoV-2 detection kit was developed on the Naica™ System. The assay exploits the system’s unique 3-color 3-channel detection capability to provide a highly sensitive and internally controlled SARS-CoV-2 assay. The targets are two distinct regions (Nucleocapside (N) and ORF1ab genes) of the SARS-CoV-2 positive-strand RNA genome, and an endogenous PCR reference detecting a human housekeeping gene. On-going studies performed in China and France confirm that Crystal Digital PCR allows to 1) reliably classify non conclusive high Ct results obtained in RT-qPCR and 2) uncover false negative results in RT-qPCR. The assay is therefore a promising complementary tool to improve Covid-19 testing and our response to the pandemic.

Learning Objectives:

1. Discover how a unique droplet microfluidic technology automates the digital PCR workflow

2. Understand how Crystal Digital PCR addresses key limitations of RT-PCR for SARS-CoV-2 detection and quantification