Development of a portable multi-step microfluidic device for point-of-care nucleic acid diagnostics

Area of Science:

• Biomedical Engineering
• Molecular Diagnostics
• Point-of-Care Testing

Background:

• The COVID-19 pandemic underscored the need for accessible diagnostic tools for respiratory diseases.
• Existing microfluidic devices are often expensive and complex for point-of-care use.
• Resource-limited areas require cost-effective and portable diagnostic solutions.

Purpose of the Study:

• To develop a cost-effective, portable, and practical microfluidic nucleic acid point-of-care test (PoCT) device.
• To enable rapid virus diagnosis in diverse settings.
• To address limitations of current complex diagnostic equipment.

Main Methods:

• Development of a microfluidic chip integrating nucleic acid extraction, reverse transcription loop-mediated isothermal amplification (RT-LAMP), and fluorescence detection.
• Optimization of homebrew RT-LAMP reagents for enhanced specificity.
• Utilizing freeze-dried RT-LAMP reagents for improved stability and ease of use.

Main Results:

• The device achieved rapid nucleic acid detection within 45-50 minutes.
• Demonstrated sensitivity in detecting SARS-CoV-2 RNA (LOD 400 copies/μL) and Trichomonas vaginalis (LOD 80 copies/μL; 0.32 cells/μL).
• Freeze-dried reagents maintained sensitivity after storage at 4°C for 30 days, with a low cost of $0.45 per reaction.

Conclusions:

• The integrated microfluidic device offers a ready-to-use, laboratory-free solution for nucleic acid detection.
• It provides a resource-independent and cost-effective alternative to complex diagnostic equipment.
• The device shows significant potential for point-of-care testing of SARS-CoV-2 and other respiratory diseases in underserved regions.