28 Microfluidic devices for DNA amplification

Amplification of nucleic acids such as DNA in vitro is one of the most consequential technologies that was developed in the past century. This technology involves a significant number of unit operations to process the samples followed by a thermal step that initiates and maintains continued duplication of a particular sequence of nucleic acid. Among the varied applications of this technology is the detection of microorganisms though the determination of the presence of unique strands of nucleic acids that are present in their genome. Over the past 30 years, these biochemical assays have been automated using miniaturization technology originating in the electronics manufacturing industry to enable their widespread use and applications even in settings that are far removed from the biochemical laboratories where they are typically performed. This chapter provides an overview of the development of microfluidic devices for automation of DNA amplification assays. It discusses the various microfluidic technologies used as well as the detection methods and amplification schemes. Devices that serve as representative examples of the technologies used are discussed in detail.