Emerging DNA Sequencing Technologies

The DNA sequencing platforms that are currently in widespread use to perform massively parallel sequencing, which as a group are currently referred to as next-generation sequencing (NGS) platforms, have enabled the genomic revolution in science and medicine. However, current NGS platforms do not represent the final stage of development of DNA sequencing technologies. A number of so-called third-generation approaches, which are already available commercially, make it possible to sequence individual DNA molecules without the need for library amplification steps. These approaches offer a number of advantages over current NGS methods including avoidance of the artifactual DNA mutations and strand biases introduced by even limited cycles of PCR; higher throughput and faster turnaround times, longer read lengths (by some platforms) that enhance de novo contig and genome assembly; higher consensus accuracy; and analysis of smaller quantities of nucleic acids which is a clear advantage in clinical settings. However, the third-generation approaches are themselves transitional to fourth-generation techniques that, while largely still in developmental phases, rely on entirely different principles of chemistry and physics to produce DNA sequence. While these fourth-generation technologies are years away from widespread clinical use, they provide a glimpse into the ever more sophisticated utilization of synthetic materials and advanced electronics that will continue to make DNA sequence analysis even faster and less costly.