The advent of Next Generation Sequencing (NGS) has revolutionized the way researchers unravel the mysteries of DNA. This cutting-edge technology promises unprecedented speed, accuracy, and affordability.
Understanding Next Generation Sequencing: At its core, NGS, also known as 'Second Generation Sequencing', represents a paradigm shift in DNA sequencing methodologies. Unlike traditional Sanger sequencing, also known as 'First Generation Sequencing', which relies on labor-intensive processes and limited throughput, NGS techniques harness high-throughput sequencing platforms to concurrently analyze millions of DNA fragments. This enables researchers to rapidly decode entire genomes and transcriptomes with efficient workflows.
Key Components and Workflow: NGS workflows typically comprise of four main stages:
Library preparation: During library preparation, DNA samples are fragmented, adapters are ligated, and amplification steps are performed to generate millions of identical DNA fragments.
Sequencing: These fragments are sequenced using different NGS platforms from companies like Illumina, Ion Torrent, and Pacific Biosciences, each of which offers distinct advantages in terms of read length, throughput, and cost.
Data analysis: The resulting raw sequenced data undergoes bioinformatic analysis to assemble the genome, identify genetic variants, and classify benign variants, pathogenic variants, and Variants of Uncertain Significance (VUS).
Interpretation: A geneticist interprets the data produced, and a genetic counsellor/ doctor conveys the reports to the concerned individual/patient and their family.
With technological advancements taking place at a rapid pace, and the costs of sequencing going down, Whole Genome Sequencing (WGS) and Whole Exome Sequencing (WES), together with Targeted Gene Panels are becoming increasingly used in clinical and diagnostic settings. The future is even brighter with Long Read Sequencing, also known as 'Third Generation Sequencing', which enables the sequencing of much longer DNA fragments than traditional short-read sequencing methods. Although short reads may capture the majority of genetic variants, long-read sequencing allows the detection of complex structural variants that may be difficult to detect with traditional methods.
-Written by Sohni Tagore
Comments