A novel passive centrifugal microfluidic architecture including modified septum valves for DNA purification using silica filter

Abstract

Efficient DNA isolation and purification underpin molecular diagnostics, enabling applications in food safety, environmental monitoring, and medical testing. Microfluidic Lab-on-a-Disk (LoaD) systems provide automation, reduced errors, and minimal resource use, making them suitable for point-of-care applications. Here we present a passive LoaD platform for DNA purification that harnesses centrifugal, pneumatic, and inertial forces to automate fluid handling without external pumps or specialized operators. The system integrates a novel Modified Septum Valve with a Centrifugo-Pneumatic Siphon Valve to control sequential reagent delivery. To simplify fabrication and reduce cost, silica paper is employed in place of conventional silica beads for nucleic acid binding. Proof-of-concept experiments using dyed water validated the rotation protocol, enabling automated binding, washing, and elution. Subsequent tests with DNA purification reagents confirmed successful DNA recovery, with purity and concentration verified by gel electrophoresis and PCR. The automated system achieved yields of ∼94.9% relative to a standard manual silica column method. Its simplicity, affordability, and strong performance highlight the potential of this LoaD approach as a foundation for integrated, sample-to-answer molecular diagnostic platforms for both research and clinical use.