A capillary-driven microfluidic device for performing spatial multiplex PCR.

Area of Science:

• Biotechnology
• Microfluidics
• Molecular Diagnostics

Background:

• Multiplex polymerase chain reaction (PCR) is crucial for syndromic testing, identifying multiple pathogens or biomarkers with overlapping symptoms.
• Existing methods can be complex and require significant sample preparation.
• On-chip integration offers potential for miniaturization and automation.

Purpose of the Study:

• To develop and demonstrate an on-chip multiplex PCR system utilizing capillary-driven fluidic actuation.
• To enable rapid sample loading and efficient reagent delivery to multiple reaction chambers.
• To validate the system's performance for detecting genetic variations.

Main Methods:

• A silicon microfluidic chip with 22 pre-spotted reaction chambers was designed.
• Capillary-driven flow was used for rapid sample loading (<10 s) via a common inlet.
• A custom clamping mechanism ensured sealing during temperature cycling.
• Custom hardware was used for temperature cycling and fluorescence imaging.

Main Results:

• The system successfully performed on-chip multiplex PCR.
• Two single nucleotide polymorphisms (SNPs), CyP2C19*2 and PCSK9, were detected.
• The chip demonstrated compatibility with parallel assays and a single-step reagent loading process.
• No active fluidic actuation, such as pumping, was required.

Conclusions:

• The developed on-chip multiplex PCR system is feasible and effective.
• The design simplifies reagent handling and eliminates the need for active pumping.
• This technology holds promise for various diagnostic applications requiring parallel genetic analysis.