How a Small Double-Stranded Trick Can Mislead Sanger Sequencing

Notwithstanding the arrival of “third-generation sequencing,” Sanger sequencing, developed in 1980, is still the most accurate and used method for sequencing, although on a smaller scale. It is a powerful resource for studying sequences and discovering polymorphisms and genes, as well as regulatory elements. There has already been described a wide range of possible problems with this very sensitive and accurate technology. Here, we show that a specific event, related to genomes rich in repetitive sequences, can mislead operators working with Sanger sequencing.