User:James Chappell/strong Promoter

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Fig.1.1:Growth of E.colicontaining the I20259 device and no plasmid (negative control) at 37oC - The growth is measured at OD600 for 6 hours
Fig.1.2:Corrected fluorescence vs time for E.coli containing I20259, see below for explanation of corrected fluorescence
Figure 1.1 it can be seen that the growth rate of the E.coli containing the I20259 is higher than that of E.coli with no plasmid. Both samples appear to have an initial lag phase for the first hour followed by the exponential phase for the remainder of the experiment. The reason for the faster growth rate of I20259 could be due to a higher initial concentration of E.coli added to the media.

Figure 1.2 shows the corrected fluorescence vs time. Corrected fluorescence was calculated by normalising by the OD600 and taking away the negative control to remove background fluorescence. As it can be seen there is an initial value at time 0, this is due to the consitutive expression of GFPmut3b in the overnight culture that was used to inoculate fresh media at time 0. From this initial value we see fluorescence increases for the remainder of the sampling, however appearing to reach a steady-state towards the end of the sampling. It is difficult to tell if this is a true steady-state due to the massive variation within this data.
There is a lot of variation within the data collected for both figure 1.1 and 1.2. The reason is firstly because of the intrinsic variation of expression in E.coli. In addition this data was a combined effort of Imperial College London Synthetic Biology Course and was collected by a group of around 30 engineers and biologist. This combined data introduces experimental variation that will have contributed to the variation seen.