Microvalve-assisted Bead-beating System for Selective Nucleic Acid Preparation from Bacteria and Viruses

Microfluidic chips are versatile tools for automatic nucleic acid extraction and are very important for nucleic acid-based detection of pathogens in aqueous samples because polymerase chain reaction can amplify nucleic acids outside of the cell. In this study, we developed a simple and effective microfluidic chip platform for selectively extracting nucleic acid from bacteria and viruses by physical adsorption and bead beating. The sample was spiked with bacteria and virus, which were pseudo-selectively adsorbed onto the microbead in the first microchamber, whereas viruses in the output solution from the first chamber were adsorbed onto the surface of microbeads in second chamber. The bacteria and viruses were efficiently lysed in each chamber by microvalve-assisted bead beating following optimization of lysis conditions. The nucleic acids of viruses were well-separated in the first chamber and those of bacteria were isolated in the second chamber.