Difference between revisions of "Part:BBa I20260:Experience"

iGEM12_OUC-China

We improved this part,and submit the improved partBBa_K737068 to the parts registry.

The absolute activity of BioBrick promoters varies across experimental conditions and measurement instruments. Researchers should choose one promoter (BBa_J23101) to serve as an in vivo reference standard for promoter activity. Drew Endy, etc demonstrated that, by measuring the activity of promoters relative to BBa_J23101, we could reduce variation in reported promoter activity due to differences in test conditions and measurement instruments by ~50%. They defined a Relative Promoter Unit (RPU) in order to report promoter characterization data in compatible units and developed a measurement kit so that researchers might more easily adopt RPU as a standard unit for reporting promoter activity. [1] However, unfortunately, there are few data about it and few teams use it as an in vivo control. This year, we detected many RFU (Relative Fluorescence Unit) curves and made it as control group. Our team wants to upload some data about it and hope other teams can use it to decrease the error.

These are RFU curves of K737069, Top10 and I20206 (in PSB4A5).

These are RFU curves of K737052 and I20206 (in PSB4A5).

Reference [1] Kelly, J.r. et al. Measuring the activity of BioBrick promoters using an in vivo reference standard. J. Biol. Eng. 3, 4 (2009).

iGEM2014 [http://2014.igem.org/Team:XMU-China# XMU-China]

iGEM2014 [http://2014.igem.org/Team:XMU-China# XMU-China] has sequenced this device. The following data was taken from this device.

We reconstructed this part, and submint the improved part BBa_K1412716 to the parts registry.

we choose the promoter J23101 to serve as an in vivo reference standard for promoter activity. In order to get the different expression intensity of BioBrick backbones, we can connect the backbones with the same promoter and the same GFP generater. Finally we can use the intensity of fluorescent protein as a charaterization data to report the expression intensity of different backbones. Unfortunately, there are few data about it, so we detected the two different backbones as examples and hope the other teams can provide more relevant data.

Measurenment

Figure 4. The plot of optical density versus time

From the plot of optical density versus time, we can conclude that the growth rate of bacteria is lower with time. We measured the sample three times parallelly, and we can know that the reproducibility of the data is acceptable. When we compare with BBa_K1412924 and BBa_K1412999, we can get that their growth rate are almost equal.

Figure 5. The plot of RFUs versus time

From the plot of RFUs versus time, we can conclude that RFUs grow linearly with time. When we compare with BBa_K1412924 and BBa_K1412999, we can get that the fluoresent expression intensity of BBa_K1412716 is higher than BBa_K141299 and whike lower than BBa_K1412924.

Figure .6 The plot of RFUs versus OD600

From the plot of RFUs versus OD600, we can conclude that RFUs grow linearly with OD600. Because the fluoresent protein expression of each bateria is contain, so when the concentration of bacteria increase, the fluoresent expression increase too. When we compare with BBa_K1412716 and BBa_K1412999, we can get that the fluoresent expression intensity of BBa_K1412716 is higher than BBa_K141299 and whike lower than BBa_K1412924.

Figure 7. The plot of RFUs/OD600 versus time

From the plot of RFUs/OD600 versus time, we know the RFUs/OD600 is a representation of the fluoresent expression intensity of unit bacteria. So we can get that the fluoresent expression intensity of BBa_K1412716 is higher than BBa_K141299 and whike lower than BBa_K1412924.

References

[1] [http://journals.aps.org/pre/abstract/10.1103/PhysRevE.82.021911 Bagh, Sangram, Mahuya Mandal, and David R. McMillen. "Minimal genetic device with multiple tunable functions." Physical Review E 82.2 (2010): 021911]