The third and last step has two parts to it. This is due to there being two primers, the initiating primer (IP) and the Vectorette primer (VP), that act in different stages. During the first part, the IP works on amplifying the primer extension while the VP remains hybridized with the product; thus, any background amplification is not carried out at this stage. However, this changes during the last and following part of PCR as the priming that is performed comes from both the IP and the VP. A lot of research has been conducted on Vectorette PCR and the applications it has in the field of biology. Scientists used Vectorette PCR to take the transgene flanking DNA and isolate it. They used this technique on the DNA belonging to mice that was next to transgene sections. From this the scientists were able to show that the use of Vectorettes is capable of facilitating the recovery and mapping of sequences in complex genomes. They’ve also found that Vectorette PCR can help in the analysis of sequences by subvectoretting when PCR products of a large size are the subject at hand. Other work has looked at developing a method using Vectorette PCR in order to accomplish genomic walking. By using Vectorette PCR, scientists were able to acquire single-stranded DNA which were obtained from PCR products in order to sequence them. From this an approach was identified in which the amplification of sequences which were previously uncharacterized was possible. This research demonstrates how novel sequences can be rapidly developed when only a known sequence of DNA is used to start. Further research has experimented with the creation of a method that progresses the isolation of microsatellite repeats. By using Vectorette PCR, researchers have found a rapid technique to accomplish this with novel, microsatellite repeats. They have attempted and succeeded in using this technique to isolate an amount of six microsatellite repeats. Vectorette PCR has also been used to not only identify genomic positions of insertion sequences (IS) but also to map them. Research on this has shed light on a way to complete the typing of microbial stains and the identification and mapping of things like IS insertion sites that reside in microbial genomes. Vectorette PCR proves useful when it comes to rapidly and simply surveying genomes’ IS elements. Transposable element, transposon, or TE is a variation of genetic elements that is capable of changing its location in a genome by a process called “jumping”.