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Introduction

Next-generation sequencing or NGS has revolutionised our understanding of biological systems. It has led to very significant and important advances in clinical research. NGS enables researchers and clinicians to study the mechanisms linked to rare genetic disorders, cancer, neonatal or infectious disease at the DNA level. This innovative approach has led to the creation of personalised diagnostics and therapies.

NGS platforms can sequence millions of DNA fragments simultaneously, allowing researchers to sequence from specific targeted regions to the entire human genome in one day.1
NGS has also enabled large-scale genomic sequencing, much more beneficial than previous sequencing technologies.

Advantages of NGS

Sanger Sequencing or First-generation sequencing had been widely used for 30 years, leading to significant advances in the understanding of the human genome.1,2 However, NGS surpassed Sanger sequencing due to the significant advantages that NGS brings. Improved sensitivity and coverage, cost-effectiveness and efficient workflow with faster turnaround time are some of the benefits of NGS.1,2,3

The NGS Workflow

There are three main steps in the typical NGS workflow.

  1. Sample preparation
  2. Sequencing
  3. Data Analysis

Sample preparation. The genomic DNA is extracted from samples (blood, tissue or saliva, for instance). The DNA is fragmented into shorter sequences followed by ligation of adapters, then amplification and enrichment.
Learn more about our Sample preparation workflow here.

Sequencing. The sequencing method is dependent on the platform being utilized. Some methods include pyrosequencing, sequencing by synthesis or ligation, and reversible terminator sequencing. Sequencing by synthesis is one of the most popular technologies because it enables researchers to sequence large amounts of genomic DNA simultaneously at high sensitivity to detect a wide range of genetic alterations, including single-nucleotide polymorphisms (SNPs), small insertions and deletions (indels), and structural variants.

Data Analysis. Bioinformatic tools or data analysis applications are used for quality control, alignment to reference sequence, and identification of pathogenic variants.

Types of NGS Applications

Depending on the area that researchers wish to focus on, NGS can be used for multiple applications.

  • Whole-genome sequencing to determine an organism’s complete DNA sequence. Learn more.
  • Whole exome sequencing to focus on the coding regions of the genome. Learn more.
  • Targeted sequencing to study specific genomic regions of interest.
  • Epigenomics to evaluate epigenetic modifications
  • RNA Sequencing for transcriptome profiling of coding and non-coding regions, identifying genes in specific cell types, and determining genetic alterations like gene fusions and single nucleotide variants (SNVs). Learn more.
  • PCR for NGS for next-generation polymerases in the NGS workflow.

At Roche Sequencing Store, you will find all the sequencing products that you need for your research.
Visit here our various product categories.

References

  1. Behjati S and Tarpey P. What is next generation sequencing? Arch Dis Child Educ Pract Ed. 2013: 98(6): 236–238.
  2. Schuster S. Next-generation sequencing transforms today’s biology. Nat Methods. 2008:16-8.
  3. Rizzo J and Buck M. Key Principles and Clinical Applications of “Next-Generation” DNA Sequencing. Cancer Prev Res (Phila). 2012: 887-900.