Cycle Sequencing

Cycle sequencing (1 ,2 ) is a simple, yet powerful tool for conveniently sequencing double-stranded DNA (dsDNA). As in other dideoxy sequencing methods (3 –5 ) dsDNA is denatured, a primer is annealed, then a complementary oligonucleotide is synthesized by a DNA poIymerase until extension is terminated by incorporation of a dideoxynucleotide. The difference is that in cycle sequencing this series of events occurs not once, but 20–30 times in succession under the control of a thermal cycler. The result is more, clearer, and stronger sequence from dsDNA for less effort.