Part:BBa_K3777013
TetR-T7(tetO)-3WJdB
Basic biosensor device for tetracycline detection.
Usage and Biology
The genetic circuit is composed of a coding sequence of which was inserted into an expression vectors with and RBS(BBa_K880005), as well as (BBa_K3386003) under the control of pMphR promoter (BBa_K3386002). The terminator we used was BBa_B0029.
When antibiotics are absent, aTF will bind to the inducible promoter（PI）and prevent RNA polymerase from initiating transcription, thus repressing the expression of reporter gene. If antibiotics are present, aTFs will bind with them and change their conformation. Therefore, they will no longer able to bind to the promoter, resulting in the expression of reporter gene. In our case, fluorescent signal increases only with the presence of antibiotics
We expressed the circuit in the E. coli BL21(DE3) cells for detection. Thus we could roughly deduce the concentration of the antibiotics in the sample according to the fluorescence intensity.
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Results
To verify the functionality of the biosensor, we performed a plate-reader experiment and measured optical density and fluorescence intensity every hour. We observed a correlation between concentration of antibiotics in the sample and intensity of fluorescent signal.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 7
Illegal NheI site found at 30
Illegal NheI site found at 1009 - 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
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