Micro real-time PCR device using a circulation pump

Abstract

This paper reports a micro real-time polymerase chain reaction (PCR) device that is integrated with a circulation pump, heaters, and thin film thermocouple (TFTC) temperature sensors. For simple operation and easy integration, the circulation pump used to circulate a fluid in a fluid channel is made by soft-lithography. The heaters are fabricated on the bottom of a glass substrate in order to provide a uniform temperature to the reaction chambers placed in the fluid channel. The temperature in each reaction chamber is continuously monitored by TFTC temperature sensors that are integrated on the top of the glass substrate. Prior to PCR experiments, performance of the heater is extensively investigated. The spatial temperature uniformity of the three reaction chambers remains within ±1 °C of the target temperatures when voltages are applied during the PCR steps (denaturation, annealing, and extension); the temporal variation of each reaction chamber is also measured to be under ±1 °C during operation of the circulation pump. During the PCR process, the fluorescence intensity is measured in order to evaluate the efficiency of DNA amplification. The amplification efficiency of the proposed PCR device is estimated to be 85 % when compared to the fluorescence intensity obtained from a commercial PCR device