Assembled Step Emulsification Device for Multiplex Droplet Digital Polymerase Chain Reaction

Area of Science:

• Biotechnology
• Molecular Biology
• Microfluidics

Background:

• Digital PCR offers high accuracy for nucleic acid quantification but faces challenges in cost, integration, and operational simplicity.
• Wider adoption of digital PCR is hindered by the expense and complexity of existing platforms.

Purpose of the Study:

• To develop a reusable, low-cost microfluidic device for simplified, multiplexed digital PCR.
• To address the challenges of cost reduction and operational simplification in digital PCR.

Main Methods:

• A reusable microfluidic device utilizing step emulsification to generate nanoliter droplet arrays for on-chip multiplex digital PCR.
• Simultaneous processing of eight samples with self-assembled monolayer droplet arrays in U-shaped chambers using mineral oil to prevent bubble formation.

Main Results:

• The device achieved sensitive detection of template DNA down to 10 copies/μL with a 4-log dynamic range.
• Successful application in quantifying HER2 copy number variation in breast cancer clinical samples, yielding results comparable to commercial digital PCR systems.

Conclusions:

• The developed microfluidic device offers a low-cost, reusable, and user-friendly solution for digital PCR.
• This innovation has the potential for broad application in various quantitative biological analyses, including clinical diagnostics.