A Rapid SARS-CoV-2 Variant Detection by Molecular-Clamping Based RT-qPCR

We applied XNA-based Molecular Clamping Technology to develop a multiplex qPCR assay for rapid and accurate detection of SARS-CoV-2 mutations. A total of 278 previously tested SARS-COV-2 positive samples originating primarily from San Francisco Bay Area were tested, including 139 Samples collected in middle January and 139 samples collected at the end of February 2021, respectively. The SARS-CoV-2 Spike-gene D614G mutation was detected from 58 samples (41.7%) collected in January 2021 and, 78 samples (56.1%) collected in February. Notably, while there were no N501Y mutation detected in samples from January, seven of the February samples were tested positive for the N501Y and D614G mutations. The results suggest a relatively recent and speedy spreading of the UK variant (B.1.1.7) in Northern California. This new Molecular Clamping technology-based multiplex RT-qPCR assay is highly sensitive and specific and can help speed up large scale testing for SARS-CoV-2 variants.