Closed chamber PCR chips for DNA amplification

Small samples of DNA can be replicated (amplified) using the polymerase chain reaction (PCR) to produce sufficient quantities for analysis in the diagnosis of disease and in forensics. Low-cost single-shot PCR devices are desirable to avoid potential contamination of the sample reaction with products of a previous reaction. After explaining the principles of PCR amplification and optical detection of the products this paper describes the fabrication of a micromachined silicon/Pyrex-based chip for the PCR using standard micromachining processes. The reaction chamber has a volume of 1 μl. Pyrex is used for sealing the chamber and its transparency enables the use of optical detection methods. Incorporated heating and sensing elements allow fast heating and control of the chip. A Peltier element is used for cooling the chip to achieve rapid temperature cycling. Some performance data are presented