Team:USP UNIFESP-Brazil/Interlab
AlgAranha Team USP-UNIFESP BRASIL
Imagine you are a Biohacker or someone very interested in Science stuff, but you have no money… How could you avoid expensive high-end equipment and yet, still obtain some data about the promoters you love?
In order to do so and draw a sketch of our promoter’s strength we have followed and updated the 2015 USP_Brazil iGEM team approach for an inexpensive and quick analysis by taking digital photos and analyzing them on open-source softwares for image processing (GIMP and ImageJ)
All test devices and controls were grown on both solid (LB-Agar) and Liquid (LB and M9) media and photos were taken by a regular cellphone under the effect of fluorescent white or blue light lamps (for exciting GFP reporter molecules). The choice of comparing both LB and M9 liquid media was based on an extensive number of reports regarding the influence of auto fluorescence of LB on measurements. Thus, we wanted to have check if the outcome of this effect would be so strong that it could be visually detected.
On a direct analysis under the blue light lamp, we can observe that there is a huge difference between M9 and LB samples (Figure 2). While we can easily observe different degrees of GFP expression on M9, it is almost impossible to do so on LB due to its intrinsic fluorescence. Even though, on both media, TD1 seems to be the strongest promoter, followed by TD2, which is similar to PC and stronger than TD3 (easier to see on M9). The last test device, TD3, seems to behave very similarly to the negative control. To sum up, at a first glance, our promoter’s strength rank is:
Figure 2 Comparison between fluorescence of Test Devices on both M9 and LB. While M9 allows us to easily compare fluorescence intensities the same is not true for LB samples due to its auto fluorescence effect.
