dideoxynucleotide

Examples of dideoxynucleotide in the following topics:

• DNA Sequencing Based on Sanger Dideoxynucleotides

  • This method is based on amplification of the DNA fragment to be sequenced by DNA polymerase and incorporation of modified nucleotides - specifically, dideoxynucleotides (ddNTPs).
  • To each reaction is added only one of the four dideoxynucleotides (ddATP, ddGTP, ddCTP, or ddTTP).
  • In dye-terminator sequencing, each of the four dideoxynucleotide chain terminators is labelled with fluorescent dyes, each of which emit light at different wavelengths .
  • Different types of Sanger sequencing, all of which depend on the sequence being stopped by a terminating dideoxynucleotide (black bars).

• Strategies Used in Sequencing Projects

  • The primer and dNTP are mixed with a small proportion of fluorescently-labeled dideoxynucleotides (ddNTPs).
  • A dideoxynucleotide is similar in structure to a deoxynucleotide, but is missing the 3' hydroxyl group (indicated by the box).
  • When a dideoxynucleotide is incorporated into a DNA strand, DNA synthesis stops.
  • Frederick Sanger's dideoxy chain termination method uses dideoxynucleotides, in which the DNA fragment can be terminated at different points.

• DNA Sequencing Techniques

  • This sequencing method is based on the use of chain terminators, the dideoxynucleotides (ddNTPs).
  • The dideoxynucleotides, or ddNTPSs, differ from deoxynucleotides by the lack of a free 3' OH group on the five-carbon sugar.
  • By using a predetermined ratio of deoxyribonucleotides to dideoxynucleotides, it is possible to generate DNA fragments of different sizes when replicating DNA in vitro.
  • In Frederick Sanger's dideoxy chain termination method, fluorescent-labeled dideoxynucleotides are used to generate DNA fragments that terminate at each nucleotide along the template strand.