A two-dimensional, self-compensated, microthermal cycler for one-step reverse transcription polymerase chain reaction applications

Thermal uniformity within a specific area is a key point for precise thermal control, especially crucial for micro biomedical applications. In this study, a new approach to improve the thermal uniformity inside a specific area was reported and used for reverse transcription polymerase chain reaction (PCR) applications. The temperature uniformity inside the reaction region of a microthermal cycler was significantly enhanced by using array-type microheaters with a two-dimensional, symmetrical, self-compensation (SC) design. With this approach, the edges of thermal profile in the heating area which commonly had significant temperature gradients can be self-compensated with an automatic function. Experimental results from infrared images showed that the percentages of the uniformity area with a thermal variation <1°C were 90.3, 99.9, and 96.8% at three PCR thermocycling temperatures (94, 55, and 72°C, respectively). It was a significant improvement over conventional block-type or serpentine-type microheaters. The performance of this proposed microthermal cycler was successfully verified by amplifying a detection gene associated with the dengue virus serotype 2. The amplification efficiency of the new microthermal cycler was statistically higher than the microheaters without SC function. © Springer-Verlag 2008.