Development of a PCR-Microreactor

The application of microfabrication technology to the development of miniaturized analytical and clinical instrumentation is an area of active interest and research. As a part of this effort, we are developing miniaturized devices and instrument components including reaction chambers, microfluidic devices (i.e. pumps, valves, and flow systems) and detection systems for biomedical applications. Specifically, a microfabricated thermal cycling instrument for application to the polymerase chain reaction (PCR) is being developed. The miniaturization of a PCR thermal cycler and associated analytical system will allow for a portable, low-power, rapid, and highly efficient bioanalytical instrument. We have successfully amplified several DNA targets from different biological systems in silicon-based microfabricated reaction chambers. These include human immunodeficiency virus (HIV) and β-globin DNA targets. Verification of the amplified target has been provided by standard agarose gel electrophoresis. Thermal modeling and infrared imaging have helped delineate optimal designs leading to efficient multiple-heater reaction chambers. Instrument efficiencies and PCR amplification results from the micro devices compare favorably to the commercial benchtop PCR systems. In the present report, we will discuss the most recent micro-PCR DNA amplification results, reaction chamber and thermal cycler optimization, fluidic manipulation and detection strategies, and the overall direction and advantages of the application of microfabrication to DNA-based microinstruments.