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5.8: DNA Sequencing by the Dideoxy Method

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    Figure 5.8.2: Sample DNA Sequencing

    The DNA to be sequenced is prepared as a single strand. This template DNA is supplied with

    • a mixture of all four normal (deoxy) nucleotides in ample quantities
      • dATP
      • dGTP
      • dCTP
      • dTTP
    • a mixture of all four dideoxynucleotides, each present in limiting quantities and each labeled with a "tag" that fluoresces a different color:
      • ddATP
      • ddGTP
      • ddCTP
      • ddTTP
    • DNA polymerase I
    Figure 5.8.3 example of a DNA sequence (455 nucleotides of the lysU gene of E. coli) courtesy of Pharmacia Biotech Inc., Piscataway, NJ


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