Digital Microfluidic Multiplex RT-qPCR for SARS-CoV-2 Detection and Variants Discrimination

Area of Science:

• Virology
• Molecular Biology
• Biotechnology

Background:

• Continuous SARS-CoV-2 mutations have increased transmissibility, prolonging the COVID-19 pandemic and straining healthcare systems.
• The emergence of variants of concern (VOCs) like Delta and Omicron necessitates rapid detection and differentiation for effective disease control.
• A point-of-care (POC) platform for multitarget detection is crucial for real-time monitoring and management of viral spread.

Purpose of the Study:

• To develop and evaluate a digital microfluidics (DMF)-based cartridge for rapid, multitarget detection of SARS-CoV-2 genotypes.
• To discriminate between the wildtype, Delta, and Omicron variants of SARS-CoV-2 using reverse transcription quantitative polymerase chain reaction (RT-qPCR).
• To assess the diagnostic capability of the DMF RT-qPCR platform for clinical applications.

Main Methods:

• Utilized a digital microfluidics (DMF) platform integrated with reverse transcription quantitative polymerase chain reaction (RT-qPCR).
• Developed a multitarget assay capable of detecting and differentiating SARS-CoV-2 wildtype, Delta, and Omicron variants.
• Evaluated performance using clinical analog samples spiked with various SARS-CoV-2 strains and 18S rDNA for internal control.

Main Results:

• The DMF RT-qPCR platform demonstrated high sensitivity (10 copies/μL) and amplification efficiency (96.1%) when tested with Omicron variant RNA samples.
• Accurate detection and discrimination of wildtype, Delta, and Omicron SARS-CoV-2 strains were achieved in clinical analog samples within 49 minutes.
• The platform successfully identified different SARS-CoV-2 strains, indicating its potential for rapid clinical diagnosis.

Conclusions:

• The developed DMF RT-qPCR platform offers a sensitive and specific solution for detecting and differentiating SARS-CoV-2 variants at the point-of-care.
• This technology can significantly aid in tracking viral spread, managing outbreaks, and informing public health strategies.
• The rapid multitarget detection capability of this platform is vital for controlling the ongoing COVID-19 pandemic.