Next Generation Sequencing

Next-generation sequencing, or NGS, is a high-throughput, massively parallel sequencing method that makes sequencing DNA or RNA quick and affordable. Due to its ability to sequence entire genomes, exomes, or specific sections of interest in a single experiment, it has completely changed genomics research as well as clinical diagnostic approaches. The following describes the operation and uses of NGS testing:

How NGS Operates:

Library Preparation: Library preparation involves fragmenting DNA or RNA samples and ligating adapters to the ends of the pieces. The sequences required for amplification and sequencing are present in these adapters.
Amplification: To create clusters of identical DNA fragments, the adapter-containing DNA fragments are subsequently amplified using a procedure known as polymerase chain reaction (PCR).
Sequencing: The amplified DNA fragments are sequenced in substantially parallel mode. While different NGS platforms use various sequencing chemicals, the fundamental idea is to ascertain the sequence of every sample fragment.
Analysis of Data: To detect genetic variants (such as single nucleotide polymorphisms, insertions, and deletions), align the sequence reads to a reference genome or transcriptome, and understand the functional implications of these variants, the sequence information collected through NGS is processed using bioinformatics tools.

NGS Testing Applications:

WGS, or whole genome sequencing: It involves sequencing an organism’s whole genome. It is used in research contexts to examine genetic variation, population genetics, and illness risk. It can offer detailed information about an individual’s genetic composition.
Whole Exome Sequencing (WES): WES focuses on sequencing the exons, or sections of the genome that code for proteins. It is used to find genetic variants linked to Mendelian illnesses, cancer, and other diseases that are expected to have functional effects.
Targeted sequencing: Targeted sequencing involves examining particular genome regions of interest, like genes linked to a specific pathology or disease. It is employed in clinical diagnostics to determine pharmacogenomic variations pertinent to drug responsiveness and to detect known disease-causing mutations.
RNA Sequencing (RNA-Seq): It is the process of sequencing the transcriptome, which contains all of a cell’s RNA molecules. It is used to measure gene expression levels, identify alternative splicing processes, and find fusion genes or new transcripts in illnesses such as cancer.
Metagenomic sequencing: It is the process of sequencing DNA from microbial communities found in ambient samples or clinical specimens. It is employed in the analysis of pathogens, microbial diversity, and the function of the microbiome in health and illness.

NGS testing has several applications in research, clinical diagnostics, and customized medicine. By offering comprehensive and high-resolution genetic information, it has facilitated advances in infectious disease, cancer, genomics, and other domains.