Principle
When cloned into a classical vector, some inserts may cause instability of this vector resulting in low yield of DNA or protein production (for protein expression vectors). The reasons for this instability are, for example, the toxicity of the insert, the secondary structure or the size of the vector. The GetStaby™ kit provides, on one hand, a plasmid containing an antidote gene (ccdA) under the control of a constitutive promoter and, on the other hand, an exclusive E. coli strain (CYS21) that contains, in its chromosome, the toxic gene (ccdB) under the control of a promoter strongly repressed in the presence of the plasmid. Contrary to classical strains, if some CYS21 bacteria loose the vector, they will not obtain a selective (growth speed) advantage and they will die. In practice, this means that at any time during bacterial growth, 100 % of the CYS21 bacteria will carry the vector even in the absence of antibiotics. These bacteria will yield high amounts of DNA or protein. Adding the Staby™ cassette (the DNA fragment encoding the CcdA antidote protein) to any vector results in stabilization of this vector in CYS21 (or any other strain containing the ccdB-poison gene in its chromosome). The Staby™ cassette is isolated from the pGetStabyA vector using restriction sites or PCR amplification.
The insertion of the Staby™ cassette into any vector is easily selected using the antidote properties of this cassette and the CYS21 bacteria (encoding the CcdB poison protein). Then, the stabilization cassette linked to any part of the vector can easily be exported to other vectors and selected using the same properties.
Legal notices
The GetStaby™ kit is covered by worldwide patents. The kit is sold under a license from the Université Libre de Bruxelles (Belgium). The kit is sold for research purpose only. A license from Delphi Genetics SA is required for any commercial use (Please, contact Delphi Genetics SA at
delphigenetics@delphigenetics.com).