Integrated microfluidic system for the identification and multiple subtyping of influenza viruses by using a molecular diagnostic approach

This study presents an integrated microfluidic system capable of rapid diagnosis of influenza infection and subtyping of influenza viruses. The viral RNA extraction module and reverse-transcription polymerase chain reaction module were integrated with an external optical detection module into the microsystem. Magnetic beads conjugated with specific nucleotide probes were first used to capture target RNA from influenza viral particles after thermolysis/hybridization processes. The hybridized target RNA was purified and collected by an external magnetic field. Finally, the extracted RNA was amplified by one-step RT-PCR products and detected by optical detection module with TaqMan fluorescence system. Moreover, the LOD was experimentally found to be 102 copies for influenza A H1/H3 and influenza B viruses. Experimental results also showed that different subtypes of influenza viruses were diagnosed by using multiplex RT-PCR process and automatically completed within 110 min in the developed microfluidic system.