What is DNA sequencing?
DNA sequencing, the process of determining the exact order of the 3 billion chemical building blocks (called bases and abbreviated A, T, C, and G) that make up the DNA of the 24 different human chromosomes, was the greatest technical challenge in the Human Genome Project. Achieving this goal has helped reveal the estimated 20,000-25,000 human genes within our DNA as well as the regions controlling them. The resulting DNA sequence maps are being used by 21st century scientists to explore human biology and other complex phenomena. Meeting Human Genome Project sequencing goals by 2003 required continual improvements in sequencing speed, reliability, and costs. Previously, standard methods were based on separating DNA fragments by gel electrophoresis, which was extremely labor intensive and expensive. Total sequencing output in the community was about 200 Mb for 1998. In January 2003, the DOE Joint Genome Institute alone sequenced 1.5 billion bases for the month.
Finding a single gene amid the vast stretches of DNA that make up the human genome – three billion base-pairs’ worth – requires a set of powerful tools. The Human Genome Project (HGP) was devoted to developing new and better tools to make gene hunts faster, cheaper and practical for almost any scientist to accomplish. These tools include genetic maps, physical maps and DNA sequence – which is a detailed description of the order of the chemical building blocks, or bases, in a given stretch of DNA. Indeed, the monumental achievement of the HGP was its successful sequencing of the entire length of human DNA, also referred to as the human genome. Scientists need to know the sequence of bases because it tells them the kind of genetic information that is carried in a particular segment of DNA. For example, they can use sequence information to determine which stretches of DNA contain genes, as well as to analyze those genes for changes in sequence, called mutations, that may cause disease.
DNA sequencing, the process of determining the exact order of the 3 billion chemical building blocks (called bases and abbreviated A, T, C, and G) that make up the DNA of the 24 different human chromosomes, was the greatest technical challenge in the Human Genome Project. Achieving this goal has helped reveal the estimated 20,000-25,000 human genes within our DNA as well as the regions controlling them. The resulting DNA sequence maps are being used by 21st Century scientists to explore human biology and other complex phenomena. Meeting Human Genome Project sequencing goals by 2003 required continual improvements in sequencing speed, reliability, and costs. Previously, standard methods were based on separating DNA fragments by gel electrophoresis, which was extremely labor intensive and expensive. Total sequencing output in the community was about 200 million base pairs for 1998. In January 2003, the DOE Joint Genome Institute alone sequenced 1.5 billion bases for the month. Gel-based
