From 2007.igem.org

Figure 1: Regardless of the cell concentration, production of GFP (Represented by the intensity of fluorescence) has a linear relationship with the concentration of AHL within the range of 0.01-1 uM.
Reaction time for Detecter Cell is 1.5 h.The fluorescence value is measured by Virian Cary Eclipse fluorescence spectrophotometer using the 3ml box at condition : Excitation wavelength-501nm(5nm),Emission wavelength-511nm(5nm),Average time 0.5s.Every sample is measured five times,between which the box was shaked for a better suspending.




Figure 2: The production of GFP is initialized when the concentration of AHL reaches to 0.01uM, then keep increasing linearly within the range of 0.01-1um, finally varies unconspicuously at values over 1um.
Reaction time for Detecter Cell is 2 h.The fluorescence value is measured by Virian Cary Eclipse fluorescence spectrophotometer using the 200ul box at condition : Excitation wavelength-495nm(10nm),Emission wavelength-515nm(10nm),Average time 5s.Every sample is measured five times,between which the box was shaked for a better suspending.

Figure 3: The dependability of this measuring method is tested by calculating the standard deviation of datas from three parallel experiments. As shown on the graph, the length of vertical lines display the value of standard deviation at a particular concentration of AHL, so the denser AHL is, the more inaccuracy the data could be.




Figure 4: Relationship between the cell concentration and the expression of GFP. Obviously, GFP accumulates with the growth of E.coli cells.