The rapid advancement of next-generation sequencing (NGS) technology has impacted all branches of life science research, from microbial genomics to the study of human disease. Compared to the previous generation of sequencing, based on Sanger chemistry and capillary electrophoresis (CE), NGS offers massively higher throughput at a fraction of the cost. For example, a typical CE sequencing run generates 50–80kb of sequence information, while the newest Illumina HiSeq® X sequencing systems produce 1.6–1.8Tb of data in a single run (1). Current Sanger CE systems can sequence a 1 megabase (1Mb) genome at a cost of approximately $2,400; by comparison, the same genome would cost just $0.07 on an Illumina HiSeq 2000 system (2).
Although several NGS platforms are available, the market at present is largely dominated by Illumina sequencing systems, with the Ion Torrent® systems from Life Technologies running a distant second (3). For any platform, the success of NGS depends, to a large extent, on using high-quality starting DNA that is quantitated accurately. This article discusses the role of DNA quantitation during typical NGS library preparation workflows.