PCR Card:

Once genetic material from a sample has been extracted, the nucleic acid of interest must be isolated and amplified. Polymerase Chain Reaction (PCR) is the process most commonly chosen to perform selective DNA amplification, and relies on thermocycling of a sample. A typical PCR thermocycling run involves 30-40 cycles, with each cycle consisting of temperature changes from 95° C (denaturation) to 60 °C (primer annealing) to 72 °C (extension). PCR efficiency is most commonly evaluated in terms of temperature transition times and thermal homogeneity of the sample, as these dictate whether or not a high-quality PCR product can be obtained in a small amount of time. Current bench-top PCR systems can take on the order of hours to complete a single run, significantly hindering the speed of nucleic acid analysis. The Madou Group has developed a rapid, disposable-card based microfluidic PCR system that has a small thermal mass resulting in rapid heating/cooling (via Peltier thermoelectric devices) and excellent thermal homogeneity. In addition, the materials and processes used to make the PCR cards are inexpensive. Amplification of an E. coli gene in the 20 uL reaction volume can be performed in well under 30 mins with a lower limit-of-detection of 10 starting copies. Although no centrifugal technologies are required for the PCR system, the same fabrication processes have been used to facilitate future incorporation onto the CD. Along those same lines, a unique ice-valve has been incorporated into the system as well.

Publications:

Guangyao Jia, Jonathan Siegrist, Chengwu Deng, Jim V. Zoval, Gale Stewart, Régis Peytavi, Ann Huletsky, Michel G. Bergeron, Marc J. Madou, (2007). A Low-Cost,

Disposable Card for Rapid Polymerase Chain Reaction, Colloids and Surf. B: Biointerfaces Special Edition, 58(1), 52-60.