Next-Generation Sequencing (NGS)

Next-generation sequencing (NGS) is an established method of simultaneously sequencing millions of fragments of DNA (or complementary DNA). In recent years, NGS has been rapidly evolved and adopted in the clinical laboratory. NGS was originally developed from pyrophosphate sequencing principle. At present, more mature application platforms are various types of Ion Torrent, Illumina, and Complete Genomics (CG). Since its first appearance more than 10 years ago, NGS technology had become increasingly mature. One of the characteristics of high-throughput sequencing technology is the fact that it has many steps and complicated procedures; any problem in any part will affect the accuracy of the test results and then affect the clinical decision-making. That means it plays an important role in precision medicine. Because high-throughput sequencing can detect numerous target genes and their mutation sites at one time, it has high sensitivity and specificity and has both qualitative and quantitative detection. Moreover, the cost of detection is lower than that of the same number of genes and loci detection. Therefore, it has broad clinical and scientific application prospects in many biomedical scientific fields, such as noninvasive prenatal screening (NIPS), mutation of tumor genes, genetic diseases, preimplantation genetic screening (PGS), preimplantation genetic diagnosis (PGD), pathogenic microorganisms, and metagenomics. As with any new technology, NGS used in the clinical laboratory is constantly evolving at the same time. This chapter is a comprehensive overview of NGS technology, including its basic principle, technology development, as well as its clinical application.