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We grew JM109 E. Coli cells that had been transformed with our plasmid in 0 to 15 mM KH2AsO4 concentrations for 12 hours to determine the time at which the cells began producing GFP. The total culture volume was 250uL with starting OD600 0.01 of cells and the appropriate concentration of KH2AsO4. The plate was grown in the plate reader, shaking at 37°C overnight. There were 3 separate wells dedicated to each concentration, as well as a negative control of wild-type JM109 cells, which does not include a GFP encoding region. A baseline GFP level was obtained from our negative control, which was subtracted from wells containing transformed cells. We measured GFP and OD600 every 30 minutes for 12 hours. Relative GFP was calculated as follows: Relative GFP = (GFP of sample - GFP of blank)/(OD600 of sample - OD600 of blank). Relative GFP allows us to compare GFP levels across different samples at one time point.  Normalized GFP was calculated as follows: Normalized GFP = (Relative GFP at time t)/(Relative GFP at starting time point). Normalized GFP allows us to compare the GFP levels of one sample at various time points. The value of normalized GFP can be less than 1 if OD600 increases more than the GFP reading of the sample. We concluded that significant GFP production began at around 3.5 hours. A concentration of 4.5 mM arsenate is necessary to induce GFP production, and maximum GFP production occurs at 15 mM arsenate or higher.