DNA sequencing is based on several methods and technologies, and is used for determining the order of nucleotides in a molecule of DNA. At the Lund University 454/Roche DNA Sequencing Facility, situated in the Ecology Building, we are running a core/service facility for traditional Sanger sequencing as well as next-generation sequencing using the 454/Roche pyrosequencing technology, developed by 454 Life Sciences.
The 454 method amplifies DNA inside water droplets in an oil solution (emulsion PCR or emPCR), in wich each droplet is containing a single DNA template attached to a single primer-coated bead that then forms a clonal colony. The sequencing surface contains many picolitre-volume wells, each containing a single bead and sequencing enzymes. Pyrosequencing uses luciferase to generate light for detection of the individual nucleotides added to the nascent DNA, and the combined data are used to generate sequence read-outs (my454.com).
Photo: Erling Jirle