Clarity Plus™ dPCR system provides a novel platform for absolute quantification of SARS-CoV-2.
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Quantification using dPCR obviates the need for a standard curve, unlike in RT-qPCR.
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The SARS-CoV-2 RT-dPCR assay showed excellent linearity, good inter- and intra-assay precision, and quantification limit of 0.25 copies/μl.
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Clarity Plus™ dPCR can potentially be adopted for clinical use and environmental surveillance.
Abstract
In recent years, the usage of digital polymerase chain reaction (dPCR) for various clinical applications has increased exponentially. In this study, a dPCR assay optimized on the Clarity Plus™ dPCR system was evaluated for the absolute quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the global coronavirus disease 2019 (COVID-19) outbreak. The assay demonstrated good inter- and intra- assay precision, accuracy, as well as excellent linearity across a range of over 6 orders of magnitude for target gene quantification. In addition, a comparison of the assay on both dPCR and qPCR platforms revealed that dPCR exhibited a slightly higher sensitivity compared to its qPCR counterpart when quantifying SARS-CoV-2 at a lower concentration. Overall, the results showed that the dPCR assay is a reliable and effective approach for the absolute quantification of SARS-CoV-2 and can be a valuable molecular tool in clinical applications such as detecting low viral loads in patients as well as in wastewater surveillance of COVID-19.
