Circullar Ferrofluid-Driven PCR Microchips
Yi Sun, Yien Chian Kwok and Nam Trung Nguyen
from: Lab-on-a-Chip Technology (Vol. 1): Fabrication and Microfluidics (Edited by: Keith E. Herold and Avraham Rasooly). Caister Academic Press, U.K. (2009)
This chapter presents novel circular ferrofluid driven microchip for rapid polymerase chain reaction (PCR). A closed-loop circular channel was fabricated on one microchip and PCR mixture together with a small ferrofluid plug was injected into the loop. An external magnet was used to drive the ferrofluid plug, which in turn propelled the PCR mixture to move around and flow continuously through three pre-set temperature zones. Parameters of PCR, such as incubation time, temperatures and number of cycles, can be fully controlled and adjusted. To improve throughput, a multi-loop ferrofluid driven microchip was also developed by designing a series of concentric circular channels on one microchip and the magnet enabled simultaneous actuation of DNA samples in all the channels. High reproducibility was achieved for different channels in the same run and for the same channels in consecutive runs. The circular ferrofluid-driven PCR microchips combine the cycling flexibility of the chamber PCR and the quick temperature transitions associated with the continuous flow (CF) PCR. Most importantly, the small footprint and simultaneous actuation make it the right candidate for parallel PCR analysis. The simple, reliable and high-throughput PCR microchips would find wide applications in forensic, clinical and biological fields read more ...