Team:RHIT/experiments

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Experiments

Analytical Method

We used Flame Atomic Absorption Spectroscopy (FlameAA) as our primary means of analyzing our project results. FlameAA is a very sensitive technique, in some cases being able to detect down to 1 part per billion. We chose this for our analytic method because it was readily available to us through the Rose-Hulman department of Chemistry and Biochemistry, and because it was a fast and accurate means of detecting the remaining concentrations of arsenic from our samples. We tested our bacteria while they were plated, with a layer of the arsenic solution in contact with the bacteria and agar. Concentrations of 100ppm, 25ppm, and 10ppm were tested at time intervals of 8 hours and 24 hours. At the end of the correct amount of time, the aqueous layer was pipetted off the plate and collected in tubes. The tubes were then diluted to a final volume of 15mL, from 6mL. This ensured we had enough sample solution to test with the FlameAA. This also allowed us to determine relative sensitivities to arsenic and approximate rates at which it could be absorbed from water.

Characterization

To characterize Part:BBa_K847004 based on its response to heavy metals, we introduced an experimental group to a copper salt solution and incubated them for 24 hours. After incubation, we spun the cells out of liquid culture, washed them, then replated them at dilutions. After letting them grow for 24 hours, we counted the CFUs on the plate and compared them to a negative control. This simple, but effective test allowed us to see what affect the part had on the survivability of cells.

Protocols