Integrating Polymerase Chain Reaction, Valving, and Electrophoresis in a Plastic Device for Bacterial Detection

An integrated plastic microfluidic device was designed and for bacterial detection and identification. The, made from poly(cyclic olefin) with integrated ink electrodes and photopatterned gel domains, DNA amplification, microfluidic valving, injection, on-column labeling, and separation. chain reaction (PCR) is conducted in a reactor containing a volume as small as 29 nL; cycling utilizes screen-printed graphite ink resistors. In situ gel polymerization was employed to form local valves that minimize convective flow of the mixture into other regions. After PCR, amplicons(products) are electrokinetically injected through the gel, followed by on-chip electrophoretic separation. intercalating dye is admixed to label the amplicons; are detected using laser-induced fluorescence. Two bacteria, Escherichia coli O157 and Salmonella, were chosen to demonstrate bacterial and identification based on amplification of of their unique DNA sequences. The limit of is about six copies of target DNA.