A miniaturized DNA amplifier: Its application in traditional Chinese medicine

A Si-based miniaturized device for the polymerase chain reaction (PCR) has been developed. The device has Pt temperature sensors and heaters integrate d on top of the reaction chamber for real-time accurate temperature sensing and control. Reaction temperature of the device is digitally controlled to achieve a temperature accuracy of +/-0.025 degrees C. The effects of PCR p rotocol optimization on the amplification performance of the surface-passiv ated chip reactor have been investigated in detail and quantitatively compa red with that of the conventional thermal cycler. In this study, four tradi tional Chinese medicine genes including Fritillaria cirrhosa, Cartharmus ti nctorius, Adenophora lobophilla, and Stephania tetrandra are used as model template. With appropriate chamber surface treatment (chlorotrimethylsilane /polyadenylic acid or SiO2 coatings), the device demonstrates amplification as efficient as that in the conventional thermal cycler at optimized MgCl2 concentration. The amplified DNA has concentration higher than 27 ng/mu L, which is sufficient for subsequent on-chip analyses and detection. Experim ental results reveal the importance of inclusion of BSA for an efficient am plification in the SiO2-passivated device and the excellent reusability of the device with a simple cleaning step.