Continuous-Flow DNA Amplification Device Employing Microheaters

Abstract

Since polymerase chain reaction (PCR) was invented, it has become one of the most significant approaches for generic identification during the last few decades. PCR is a useful procedure to magnify the number of copies of a specific DNA template exponentially. Integrated microfluidic DNA amplification devices that employ a serpentine polydimethylsiloxane microchannel, a glass cover with micro heaters and sensors, and a cooling polymethylmethacrylate channel are demonstrated in the present study. With the aid of commercial computational fluid dynamics software, we design the continuous-flow DNA amplification device. The influences of various chip materials, water cooling conditions and geometric parameters on the temperatures of the chip are expressed. Using the MEMS process, two micro aluminum heaters and sensors are fabricated. This device represents the first demonstration of Al heaters and sensors integrated in continuous-flow PCR microfluidics. The LabVIEW control module is used to manage the temperatures of the micro-domain heating. One important feature of this system is the temperature of the annealing zone is controlled by the flow rate of the fluid inside a water channel under the glass chip. The cooling channel cannot only provide great thermal insulation between two temperature zones at the opposite sides of the chip, but also improve the temperature uniformity at the chip center temperature zone. By utilizing an IR thermometer, the images of the surface temperature distributions are captured to show the effects of the employed microheaters and the cooling channel on the thermal field of the PCR device. Finally, we find the temperature regions generated in the present device are suitable for completing the PCR process.