Size separation of extended and terminated fragments
Figure 1.8 Dideoxy DNA sequencing. Chain termination occurs on incorporation of a specific dideoxynucleotide into the nascent complementary DNA strand synthesized from the 3' end of the annealed primer; different sequencing reactions are set up with one of four ddNTPs and all four dNTPs. Depending on where the ddNTP is incorporated, specific fragment lengths result. For a ddTTP reaction in this example, fragments of 2, 8, 11, and 14 nucleotides plus the length of the primer are observed indicating a T at these positions in the sequence. Sequence read from +1 after 3' end of primer: GTCCCGCTGATGGTA
March 2006 human reference sequence (NCBI build 36.1) produced by the International Human Genome Sequencing Consortium
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