Automated solid phase DNA extraction on a lab-on-a-disc with two-degrees of freedom instrumentation

Area of Science:

• Biotechnology
• Microfluidics
• Point-of-care diagnostics

Background:

• Lab-on-a-disc (LoaD) technology offers integrated solutions for diagnostics but faces challenges with complex valving systems.
• Existing LoaD designs often require intricate valves for fluid control, increasing complexity and failure points.
• There is a need for simplified LoaD platforms that eliminate complex valving for improved reliability and manufacturing.

Purpose of the Study:

• To develop and demonstrate an automated biological workflow on a LoaD device without integrated valving.
• To showcase a novel fluid manipulation approach for reagent actuation and incubation on a microfluidic platform.
• To evaluate the performance of the simplified LoaD platform in DNA purification compared to existing methods.

Main Methods:

• Utilized a Two Degrees-of-Freedom (2DoF) custom centrifuge to control fluid flow direction.
• Implemented a 360-degree fluid manipulation strategy via planetary gear motion for sequential reagent delivery.
• Designed intermediate flow chambers to prevent cross-contamination between assay steps.

Main Results:

• Successfully automated a complex biological workflow on a LoaD device without any embedded valves.
• Achieved a two-fold increase in DNA yield at higher cell concentrations compared to commercial spin-column kits.
• Demonstrated the capability for infinite sample incubation times and efficient platform utilization.

Conclusions:

• The developed system integrates 2DoF and centrifugal microfluidics to automate biological workflows on LoaDs, eliminating the need for complex valves.
• The simplified LoaD platform offers superior DNA extraction performance for higher cell counts and enhanced reliability.
• This valve-less approach provides a straightforward and robust solution for automated biological assays, particularly in diagnostic applications.