Difference between revisions of "Team:WashU StLouis/parts"

The 2015 WashU iGEM conducted a series of induction experiments to determine the validity of part K314100. The results obtained suggest that the part isn’t subject to inducer concentrations. The part either fluoresced at a constant, high level or didn’t fluoresce at all when tested.

The team transformed the part into DH10B twice. The colonies of the first transformation looked like this:

The cells largely appeared red. The WashU iGEM team then conducted an induction experiment to test how the cells fluoresced at different concentrations of aTc. The team pipetted cell culture into different aTc concentrations serially diluted across 8 wells. Results from this induction experiment are shown below.

While the part had a 1.3x increase between the lowest and highest inducer concentrations, the fluorescence increase was not uniform across all concentrations; fluorescence decreased at certain concentrations when it should’ve been increased.

The team proceeded with a second transformation to test the part even further. Colonies from that transformation are shown below.

Cells were largely colorless, with few red colored colonies to be found. Using the same procedure from the first experiment, the team ran a second induction experiment on these colonies to observe whether red fluorescence increased with aTc concentration. The results from that experiment are shown below.

The colonies exhibited no remarkable fluorescence regardless of the aTc concentration. At this point in time, the team hypothesized that the colonies from the first transformation were simply different than the colonies from the second transformation, perhaps as a result of homologous recombination. The team decided to run a third induction experiment, with the same protocol used in the previous two experiments, to determine the validity behind this assertion. Two colonies were picked from the first transformation; one colony was picked from the second transformation. The results from this experiment are shown below.

Values for each colony are consistent with what was obtained in their respective experiments. While the team didn’t sequence the parts in each colony, it suspects that two separate strains had been produced, in which the part had been mutated in some manner. Regardless, the team holds little confidence in the effectiveness of this part.