A microfluidic device for on-chip agarose microbead generation with ultralow reagent consumption

Area of Science:

• Biotechnology
• Microfluidics
• Biochemistry

Background:

• Water-in-oil microdroplets serve as high-throughput microreactors for biochemical reactions.
• Incorporating agarose into microdroplets enables sol-gel switching, enhancing applications like Polymerase Chain Reaction (PCR) by preserving monoclonality.

Purpose of the Study:

• To develop a new microfluidic method for generating agarose-in-oil microdroplets.
• To integrate features like minimized dead volume, on-chip cooling, and in situ monitoring into the microdroplet generation process.
• To demonstrate the utility of the generated agarose microbeads for biochemical applications.

Main Methods:

• Utilized a flow-focusing microchannel network and a 'push-pull' method for microdroplet generation at room temperature.
• Integrated a cooling system using embedded copper wires within the microfluidic device.
• Demonstrated on-chip temperature-triggered DNA isothermal amplification within the gelified microbeads.

Main Results:

• Successfully generated stable agarose microdroplets at room temperature with minimized inlet dead volume.
• The transition to gelified microbeads facilitated enhanced stability and manipulation.
• Demonstrated successful on-chip isothermal DNA amplification, showcasing the system's potential for biochemical assays.

Conclusions:

• The developed microfluidic device offers a high-throughput method for generating agarose microbeads with no dead volume.
• This technology provides a stable platform for compartmentalized biochemical reactions and in situ monitoring.
• The system is well-suited for various biochemical applications, including temperature-triggered amplification reactions.