Genome sequencing is the process of determining the order of nucleotide bases (A, T, C, and G) in an organisms genome, which is the complete set of DNA sequences in an organism. Whole genome sequencing (WGS) is a type of genome sequencing that determines the entirety, or nearly the entirety, of an organisms chromosomal DNA as well as DNA contained in the mitochondria and, for plants, in the chloroplast. WGS has largely been used as a research tool, but it is being introduced to clinics and may be an important tool in the future of personalized medicine.
Scientists conduct whole genome sequencing by following these four main steps:
- DNA extraction: DNA is extracted from the organisms cells.
- DNA fragmentation: The DNA is broken into smaller pieces.
- DNA sequencing: The DNA fragments are sequenced to determine the order of nucleotide bases.
- Data analysis: Computer analysis tools are used to compare sequences from multiple organisms and identify differences.
Whole genome sequencing has improved disease detection by providing detailed and precise data for identifying outbreaks sooner. It is also used to characterize bacteria and track outbreaks, which greatly improves the efficiency of how PulseNet, a national network of public health and food regulatory agency laboratories, detects and responds to foodborne outbreaks.
The Genome Sequencing Program, initially created to sequence the human genome, uses genome sequencing to identify genes and genomic variants underlying human inherited disease.
