A microchannel chip for continuous-flow polymerase chain reaction (PCR) was developed using transparent materials. The microchannel was fabricated on a quartz glass substrate using standard photolithography and wet-etching techniques, and was sealed by another quartz glass substrate. Two indium-tin-oxide (ITO) films were deposited on the etched substrate as a thermal source. A layer of SiO2 served as an insulated layer was then deposited on the ITO heaters. Next, thin ITO films served as temperature sensors were then patterned using lift-off techniques._To confirm the temperature distribution in the microchannel, we measured the fluorescence spectra of an aqueous solution of 1-pyrenesulfonic acid sodium salt (PS-Na), which is a temperature-indicator dye, in the microchannel under a continuous solution flow. The results confirm that the temperature distribution on the microchannel’s ITO films was almost uniform (within ±2_) under two flow rates (56 nl/min and 152 nl/min). The slightness of this deviation indicates that the ITO films integrated into the microchannel chip can be very useful as a thermal source and temperature sensor for PCR. An amplification of a 450-bp segment of Escherichia coli HB101 was successfully performed by two-stage (94_ and 67_) thermal cycling on the chip device.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2003 Nanotechnology Conference and Trade Show, Volume 1
Published: February 23, 2003
Pages: 86 - 89
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topics: Micro & Bio Fluidics, Lab-on-Chip