Validation of a fully integrated microfluidic array device for influenza A subtype identification and sequencing.

Rapid detection and identification of influenza virus is becoming increasingly important in the face of concerns over an influenza pandemic. A fully integrated and self-contained microfluidic device has been developed to rapidly identify influenza A hemagglutinin and neuraminidase subtypes and sequence portions of both genes. The device consists of a DNA microarray with 12 000 features and a microfluidic cartridge that automates the fluidic handling steps required to carry out a genotyping assay for pathogen identification and sequencing. The fully integrated microfluidic device consists of microfluidic pumps, mixers, valves, fluid channels, reagent storage chambers, and DNA microarray silicon chip. Microarray hybridization and subsequent fluidic handling and reactions were performed in this fully automated and miniature device before fluorescent image scanning of the microarray chip. A micromixing technique based on gas bubbling generated by electrochemical micropumps was developed. Low-cost check valves were implemented in the cartridge to prevent cross talk of the stored reagents. The genotyping results showed that the device identified influenza A hemagglutinin and neuraminidase subtypes and sequenced portions of both genes, demonstrating the potential of integrated microfluidic and microarray technology for multiple virus detection. The device provides a cost-effective solution to eliminate labor-intensive and time-consuming fluidic handling steps and allows the detection and identification of influenza virus in a rapid and automated fashion.