Tet-One or Tet-On 3G: which system should I choose?
Tet-One or Tet-On 3G: which system should I choose?
In terms of technology, the Tet-One and Tet-On 3G systems are essentially identical. Both activate expression in the presence of doxycycline, using the Tet-On 3G transactivator to activate expression from a TRE3G promoter.
For most applications, the Tet-One system is the best choice because it provides all components on a single vector, making it far easier to set up tightly controlled expression of your gene of interest. In that respect, Tet-inducible expression is as easy to use as any constitutive expression system. Tet-One is based on an all-in-one design that has shown up to 25,000-fold induction.
So when might a researcher choose a Tet-On 3G system instead? Even in a system that offers 25,000-fold induction, basal expression is not zero. Transcripts can be detected in sensitive assays such as qRT-PCR. If you need the absolute lowest level of basal expression (for highly toxic proteins for example) and have the willingness to screen clones after sequential delivery of the two vectors, it is possible with Tet-On 3G to find clones that have the lowest possible basal transcription.