Editing Plasmid (section)

=== Suicide Vectors (plasmids) ===
Suicide vectors are plasmids that are unable to replicate in the host cell and therefore have to integrate in the chromosome or disappear.<ref>{{cite book |doi=10.1016/B978-0-12-385075-1.00024-X |chapter=Synthetic Biology in Cyanobacteria |title=Synthetic Biology, Part A |series=Methods in Enzymology |date=2011 |last1=Heidorn |first1=Thorsten |last2=Camsund |first2=Daniel |last3=Huang |first3=Hsin-Ho |last4=Lindberg |first4=Pia |last5=Oliveira |first5=Paulo |last6=Stensjö |first6=Karin |last7=Lindblad |first7=Peter |volume=497 |pages=539–579 |pmid=21601103 |isbn=978-0-12-385075-1 |quote=Integrative plasmids are in most cases suicide vectors, that is, vectors that are unable to replicate in the destination host and therefore must either integrate or disappear, and hence, any plasmid that can be efficiently transferred into the recipient may be used. }}</ref> One example of these vectors are pMQ30 plasmid. This plasmid has SacB gene from ''Bacillus subtilis'' which can be  induced by sucrose and it'll be lethal when expressed in Gram-negative bacteria.<ref>{{cite journal |last1=Quandt |first1=Jürgen |last2=Hynes |first2=Michael F. |title=Versatile suicide vectors which allow direct selection for gene replacement in Gram-negative bacteria |journal=Gene |date=May 1993 |volume=127 |issue=1 |pages=15–21 |doi=10.1016/0378-1119(93)90611-6 |pmid=8486283 }}</ref> The benefit of this system( two-step success monitoring ) shows when the experiment design needs a target gene to be integrated into the chromosome of the bacterial host. In the first step after transforming the host cells with the plasmid, a media with specific antibiotic could be used to select for bacteria that contain the plasmid. The second step makes sure that only the bacteria with integrated plasmid would survive. Since the plasmid contain the SacB gene that will induce toxicity in presence of sucrose, only the bacteria would survive and grow that has the plasmid integrated in their chromosome.