A Self-Priming Microfluidic Chip with Cushion Chambers for Easy Digital PCR

Area of Science:

• Biotechnology
• Microfluidics
• Molecular Diagnostics

Background:

• Digital polymerase chain reaction (dPCR) requires precise sample partitioning for accurate quantification.
• Existing dPCR methods can be complex, costly, or lack robustness.
• Microfluidic technologies offer potential for simplified and integrated dPCR systems.

Purpose of the Study:

• To develop a self-priming, easy-to-operate microfluidic chip for digital polymerase chain reaction (dPCR).
• To enhance the robustness of sample partitioning in microfluidic dPCR devices.
• To demonstrate the chip's capability for absolute quantification of target genes.

Main Methods:

• Fabrication of a polydimethylsiloxane (PDMS)-based microfluidic chip with integrated cushion chambers.
• Utilized a de-gassed PDMS layer and multi-level vertical branching microchannels to generate negative pressure for autonomous sample partitioning.
• Evaluated chip performance using a 10-fold serial dilution of a DNA template for absolute quantification.

Main Results:

• The proposed microfluidic chip demonstrated self-priming capability with a single inlet, autonomously partitioning samples.
• Cushion chambers ensured robust sample partitioning, preventing sample loss or cross-contamination.
• The chip achieved excellent performance in the absolute quantification of a target gene across a wide dynamic range.

Conclusions:

• The developed PDMS microfluidic chip provides a robust and user-friendly platform for digital polymerase chain reaction (dPCR).
• Its ease of operation, low cost, and high robustness make it suitable for widespread dPCR applications.
• This technology is particularly promising for advancing digital PCR in resource-limited settings.