nucleotide sequencing assay evidence chain termination sequencing evidence eco Chain termination sequencing, also called Sanger sequencing after its developer, uses dideoxynucleotide triphosphates (ddNTPs) as DNA chain terminators. Single-stranded DNA template, DNA primer, DNA polymerase, fluorescently or radioactively labeled nucleotides, and one of four ddNTPs are added together in each of four separate sequencing reactions. The synthesized and labeled DNA fragments from each of the four reactions are denatured, separated by size by gel electrophoresis, and visualized by autoradiography or UV light. The ddNTPs lack an OH group so the next dNTP cannot be attached, causing chain termination. 2010-11-15T04:46:31Z dye terminator sequencing A type of nucleotide sequencing assay in which DNA sequence is determined by addition of a primed DNA template to a reaction mixture, followed by addition of DNA polymerase, deoxynucleosidetriphosphates (dNTPs - one of which may be radiolabeled), and one of four di-deoxynucleotidetriphosphates (ddNTPs), after which DNA elongation is terminated and the DNA is separated by size and imaged. mchibucos ECO:0000225 Sanger sequencing