NGS (Next-generation Sequencing) is a powerful tool that utilises the high-throughput and massively parallel sequencing approach, which has greatly improved sequencing efficiency while maintaining a high level of accuracy.The first-generation sequencing (Sanger sequencing) can only sequence a single DNA fragment at a time, while NGS can sequence and analyse hundreds to thousands of genes simultaneously, this allows scientists to rapidly obtain results that cover the entire human genome.

Compared to the first-generation sequencing, NGS has a significantly higher sequencing throughput and sequencing speed. This has made the whole genome sequencing process less expensive and time-consuming, reducing the cost from nearly 30 billion USD to about 1000 USD and the time required from 10 years to just 1 day. Besides, NGS has a higher sensitivity, which allows new or rare mutations within the target region of the genome to be detected by deep sequencing. Therefore, NGS can perform complex analysis that is beyond the capacity of the first-generation sequencing. For example, performing a large-scale whole-genome sequencing to analyse a complete human genome, or using transcriptome sequencing for mRNA, miRNA expression and RNA splicing analysis.

With the ultra-high throughput, scalability and speed offered by NGS, a wide range of applications can now be performed by scientists to study biological systems at an unprecedented level. Results generated from NGS can be combined with genomic data and bioinformatic studies to provide useful information for diseases and population-wide genomic research. Clinical applications of NGS include sequencing cancer samples to study rare somatic mutations, analysing epigenetic factors and revealing disease-related alleles.