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

Area of Science:

• Molecular Biology
• Virology
• Diagnostic Technologies

Background:

• Real-time reverse transcription-polymerase chain reaction (RT-qPCR) is the standard for SARS-CoV-2 detection but has limitations in identifying low viral loads.
• Pre-analytical and technical challenges can affect the sensitivity of conventional RT-qPCR assays.

Purpose of the Study:

• To develop and evaluate a digital RT-PCR (dRT-PCR) on-chip method for enhanced SARS-CoV-2 detection.
• To assess the sensitivity of dRT-PCR compared to RT-qPCR for viral load quantification.

Main Methods:

• Developed a novel on-chip dRT-PCR assay for SARS-CoV-2 detection.
• Utilized TaqMan™ Assays targeting the N (Nucleocapsid) and S (Spike) proteins.
• Employed the QuantStudio™ 3D Digital PCR instrument for analysis.
• Applied the method to nasopharyngeal swabs from asymptomatic subjects in the UNICORN Study.

Main Results:

• The developed dRT-PCR method demonstrated superior sensitivity compared to standard RT-qPCR.
• The assay successfully detected SARS-CoV-2 in samples with low viral loads that might be missed by RT-qPCR.
• Quantification of viral load was achieved using specific N and S protein assays.

Conclusions:

• Digital RT-PCR is a highly sensitive method for SARS-CoV-2 detection and quantification.
• This on-chip dRT-PCR approach offers a promising advancement over conventional RT-qPCR, particularly for low viral load scenarios.
• The technology could be valuable for monitoring viral load in asymptomatic populations and improving diagnostic accuracy.