Research Information System
in: Plant omics: Trends and applications, K.R. Hakeem,H. Tombuloglu,G. Tombuloglu, Editor, Springer, London/Berlin , Zürich, pp.109-136, 2016
It has been more than 35 years since the development of the
groundbreaking method for DNA sequencing by Frederick Sanger and
colleagues. This revolutionary study triggered the improvement of new
methods that have provided great opportunities for low-cost and fast DNA
sequencing. Strikingly after the Human Genome Project, the time
interval between each sequencing technology started decreasing while
amount of scientific knowledge has continued growing exponentially.
Considering Sanger sequencing as the first generation, new generations
of DNA sequencing have been introduced consequently. The development of
the next-generation sequencing (NGS) technologies has contributed to
this trend substantially by reducing costs and producing massive
sequencing data. Hitherto, four sequencing generations have been
defined. Second-generation sequencing that is currently the most
commonly used NGS technology consists of library preparation,
amplification, and sequencing steps while in third-generation
sequencing, individual nucleic acids are sequenced directly in order to
avoid biases and have higher throughput. Recently described
fourth-generation sequencing aims conducting genomic analysis directly
in the cell. Classified to different generations, NGS has led to
overcome the limitations of conventional DNA sequencing methods and has
found usage in a wide range of molecular biology applications. On the
other hand, plenty of technical challenges, which need to be deeply
analyzed and solved, emerged with these technologies. Every sequencing
generation and platform, by reason of its methodological approach,
carries characteristic advantages and disadvantages which determine the
fitness for certain applications. Thus, assessment of these features,
limitations, and potential applications help shaping the studies that
will determine the route of omic technologies.