AAT Bioquest

What is the difference between Exome Sequencing and Whole Genome Sequencing (WGS)?

Posted February 16, 2022


Whole Genome Sequencing

  • Sequences the complete DNA of an organism, including coding and noncoding nuclear DNA as well as mitochondrial DNA
  • Does not require a capture step, which is necessary in exome sequencing
  • Can uncover variation in any part of the human genome
  • Enables researchers to generate vast quantities of data, which can then be analyzed
  • The goal is to look for genetic aberrations such as single nucleotide variants, insertions, and deletions
  • Requires more sequencing reagents and generates very large datasets that require sophisticated bioinformatics expertise to decipher, increasing the cost and time required for analysis

Exome Sequencing

  • Targets and sequences only coding regions of the genome, referred to as the exome
  • Capture-based method
  • Exomes can be sequenced at much greater depth (the number of times the nucleotide is sequenced), which provides more confidence in low frequency alterations
  • Requires fewer sequencing reagents and generates smaller databases that take less time to perform bioinformatics analysis than whole genome sequencing and is more cost-effective too
  • Often used in clinical care to provide greater confidence as well as keep the cost down and provide better opportunity for insurance reimbursement
Additional resources

Comparison of Exome and Genome Sequencing Technologies for the Complete Capture of Protein‐Coding Regions