Dideoxy DNA sequencing

Dideoxy DNA sequencing (Section 28.6) A biochemical method for sequencing DNA strands. 

The dideoxy DNA sequencing method begins with the denaturation of double-stranded DNA (dsDNA) into single-stranded DNA. The ssDNA is then annealed with a fluorescent dye-labeled primer, which is an oligodeoxynucleotide 20 bases long. The heteroduplex formed is then incubated in four separate reactions. 

Sequenase. [U.S. Biochemical] T7 DNA polymerase enzyme for dideoxy DNA sequencing. 

Figure 20 DE-MALDI-TOF spectrum of a mixture of Sanger dideoxy DNA sequencing reactions containing about 0.1 pmol of each termination fragment generated by primer extension on a 50-base-pair template. The matrix used was a mixture of of 3-hydroxypicolinic acid and picolinic acid including diammonium citrate to complex metal ions (prepared according to Wu et al. [98]). The four panels correspond to termination with (A) ddA. (B) ddC, (C) ddG, and (D) DDT. (From Ref. 82.)...

Seela et al7 reported the synthesis of 7-deazapurine (pyrrolo[2,3-djpyrimidine) 2 -deo)yrihonucleosides (88), ineluding (3-d- and p-L-enantiomers, fluoro-derivatives and 2, 3 -dideo3yrihonueleosides with well-defined stereochemistry. These eompounds have potential applications as antiviral or anticancer agents (7-deazapurine nueleosides), and the 7-deazapurine nucleoside triphosphates are used in Sanger dideoxy DNA-sequencing. 

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