How does whole exome sequencing work?

Whole Exome Sequencing (WES) is a technique that focuses on sequencing the protein-coding regions (the exome) of the genome. Non-coding regions are not tested in this technique. 

WES can be broken up into 6 main steps. Here’s how the process works: 

1. DNA Extraction: DNA is extracted from an individual’s sample.
2. DNA Fragmentation: The extracted DNA is broken down into smaller fragments using physical or enzymatic fragmentation techniques. 
3. Adapter Ligation & Amplification: DNA adapters are attached to the fragments, which are then amplified through PCR (Polymerase Chain Reaction).
4. Target Enrichment: The fragments corresponding to the exomes (protein-coding regions) are isolated using biotinylated probes complementary to the exomic regions of interest. The probes bind to the desired sequences and unwanted sequences are washed away, enriching the target fragments. 
5. Sequencing: The selected protein-coding exon sequences obtained at the end of the target enrichment are sequenced using Next-Generation Sequencing (NGS) technology to detect mutations.
6. Data Analysis: The sequencing data is analyzed to interpret the genetic variations using methods such as bioinformatics and computational algorithms.