Team:HBUT-China/Results

We will show our results from three aspects:
Qualitative analysis:
After 12 hours of incubation(LB,37℃,200r/min), we observed the bacteria on a fluorescence microscope.
In the medium with the addition of nickel ions, we can see visible red fluorescence.
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In other media, there is no such phenomenon. The whole vision is black.
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So our device only responds to nickel ions.
Quantitative analysis:
At the initial induction concentration of OD0.8, and the Induction time is 2 hours. Under this condition, the nickel ion concentration has a significant function relationship with the fluorescence intensity.
Especially in the nickel ion concentration of 10-6mmol / L to 10-4mmol / L between.
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model:
At first, we made some assumptions.
Assumptions:

The degradation of and other substances are linear.

Each cell has the same state.

The reaction in the process satisfies the first-order kinetic reaction.

Then we got some conclusions through modeling.
Incomplete Repression:
Under incomplete repression, the bacteria express red fluorescent proteins without the presence of nickel ions.
The incomplete repression of promoters is a major issue in our fluorescence system. This issue was particularly observed in following diagram.
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The solution of this differential equation is as follows:
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Cytotoxicity:

We found that a high concentration of nickel ions will reduce the expression of fluorescence, because nickel ions have cytotoxicity.

The July 20 experimental data is as follows:

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The different equation of the red fluorescent protein is then modified to:

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Where

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