Rapid detection of genetically modified organisms on a continuous-flow polymerase chain reaction microfluidics

The ability to perform DNA amplification on a microfluidic device is very appealing. In this study, a compact continuous-flow polymerase chain reaction (PCR) microfluidics was developed for rapid analysis of genetically modified organisms (GMOs) in genetically modified soybeans. The device consists of three pieces of copper and a transparent polytetrafluoroethylene capillary tube embedded in the spiral channel fabricated on the copper. On this device, the 11355 and Tnos sequences were successfully amplified within 9 min, and the limit of detection of the DNA sample was estimated to be 0.005 ng mu l(-1). Furthermore, a duplex continuous-flow PCR was also reported for the detection of the P35S and Tnos sequences in GMOs simultaneously. This method was coupled with the intercalating dye SYBR Green I and the melting curve analysis of the amplified products. Using this method, temperature differences were identified by the specific melting temperature values of two sequences, and the limit of detection of the DNA sample was assessed to be 0.01ng mu l(-1). Therefore, our results demonstrated that the continuous-flow PCR assay could discriminate the GMOs in a cost-saving and less time-consuming way. (C) 2008 Elsevier Inc. All rights reserved.