Droplet-Based Microfluidic Chip Design, Fabrication, and Use for Ultrahigh-Throughput DNA Analysis and Quantification

Area of Science:

• Biomolecular analysis
• Molecular diagnostics
• Microfluidics

Background:

• DNA is a crucial biomarker for detecting contamination, infection, and disease.
• Quantitative PCR (qPCR) is the primary method for DNA detection but has limitations like inhibitor sensitivity and primer design challenges.
• Digitalization of analysis, by compartmentalizing DNA molecules, addresses these qPCR limitations.

Purpose of the Study:

• To introduce the principles of digital droplet PCR (ddPCR).
• To provide guidelines for fabricating, setting up, and utilizing a ddPCR platform.
• To present procedures for DNA detection and quantification from purified samples and individual cells.

Main Methods:

• Microfluidics for generating millions of picoliter-volume water-in-oil droplets.
• In situ amplification of individual DNA molecules within droplets.
• Digital data acquisition and analysis for absolute DNA quantification.

Main Results:

• ddPCR overcomes limitations of qPCR, including issues with similar DNA templates, inhibitors, and primer design.
• The microfluidic approach enables high sensitivity and absolute DNA concentration measurements.
• Procedures are provided for both purified DNA and direct analysis of individualized cells.

Conclusions:

• Digital droplet PCR (ddPCR) provides highly sensitive and accurate DNA quantification.
• Microfluidics-based ddPCR is a powerful tool for various applications, including cancer research.
• This technology serves as a foundation for advanced in vitro analytical pipelines.