Integrated microfluidic device for DNA extraction using electric valves

Deoxyribonucleic acid (DNA) encodes the genetic instructions that govern the development and function of living organisms, and its isolation is a critical prerequisite for downstream applications such as sequencing and diagnostic assays. Here, we present an integrated lab-on-a-chip platform that automates genomic DNA extraction by combining a passive micromixer for chemical cell lysis with a silica-based filtration unit. The system comprises three microfluidic chips for mixing, lysis, and purification, interconnected by electrically actuated valves to precisely route fluids through each stage. We systematically optimized key parameters fluid velocity, filter thickness, lysis temperature, and cell concentration, and identified the ideal operating conditions: 2.5 × 10⁶ cells/mL input, 65 °C lysis, a single silica filter, and a 25 mL vacuum chamber to drive flow. Under these settings, the device delivered 147.23 ± 29.04 ng/µL DNA, corresponding to approximately 90% extraction efficiency relative to a commercial silica-column kit. Finally, we confirmed the integrity of the recovered DNA by PCR amplification and agarose-gel electrophoresis on seven representative samples. These results demonstrate that our multi-chip microfluidic platform provides rapid, efficient, and semi-automated genomic DNA isolation, offering a robust alternative to conventional bench-top methods.