Bronze medal criterion #5
To fulfil bronze medal criterion #5, our team added characterization data to part BBa_K2137001.
This part is a yeast promoter, CUP1, upstream of GFP. CUP1 is a copper-inducible promoter.The original characterization experiments for the promoter were limited by several design flaws. In the original experiments, cells were grown in YPGal media, which is a complex medium. Because of this, it is possible that there was copper in the medium, which would have induced the promoter and prevented us from obtaining accurate characterization data for the promoter. The YPGal media was also not selective for cells containing the vector, meaning that the vector may have been lost in a portion of the cells used for characterization. Finally, the experiments characterized the promoter using only a copper ion concentration of 200 µM.
This year, to improve the characterization of this part, we sought to obtain characterization data for the promoter after growing the cells in a defined medium, WO. This way, we could be sure there was no copper in the growth medium, and that any promoter activity was due to the added copper. This defined media also allowed for selection of cells containing the vector, ensuring that our characterization experiments did not include cells that had lost the vector. Finally, we chose to characterize the promoter by induction with a range of copper concentrations.
The figure above displays the OD-corrected fluorescence of the cells containing the Cup1-GFP fusion 8 hours after the addition of varying amounts of copper. These data represent a more robust set of experimental data characterizing the induction of the Cup1 promoter by addition of copper.
For more details, visit the BBa_K2137001 registry page.