Continuous‐Flow PCR Microfluidics for Rapid DNA Amplification Using Thin Film Heater with Low Thermal Mass

Abstract

We have described a compact capillary‐based continuous‐flow polymerase chain reaction (PCR) microfluidics device, which uses flexible thin film heaters with low thermal mass to construct three isothermal zones. Due to the decreased thermal mass of flexible thin film heater, the low power supply and rapid thermal response was obtained. The energy consumption of a 33‐cycle continuous‐flow PCR was less than 0.0088 kW h, which is much lower than that of the metal block or liquid bath based capillary continuous‐flow PCR microfluidics. Special attention was also paid on the surface passivation of the capillary inner surface based on the competing bovine serum albumin (BSA), and the results showed the effect of dynamic passivation was superior to that of static passivation. With the help of the dynamic passivation, the 249 bp human β‐actin gene fragment was amplified in 15 min, which is several times faster than that of the conventional PCR machine. In addition, the effect of initial DNA template concentrations on continuous‐flow PCR was also investigated. The concentration limit of DNA template reached 0.18 ng µl⁻¹, which can satisfy the requirements from different application fields.

Keywords:

• Continuous‐flow
• polymerase chain reaction (PCR)
• microfluidics
• DNA amplification
• thin film heater

Acknowledgments

This research is supported by the National Natural Science Foundation of China (60378043; 30470494) and the Natural Science Foundation of Guangdong Province (015012; 04010394).