Team:Aberdeen Scotland/Registry

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University of Aberdeen iGEM 2009

BioBrick Experience

BBa_R0051

Aberdeen_Scotland 2009

The initial gel worked although the obvious confirmation was not possible due to the very small fragment size (49bp).But later it was confirmed following its usage by forming the part BBa_K182002 through the PCR gel analysis and the sequencing.The plasmid miniprep also worked.


BBa_C0040

Aberdeen_Scotland 2009

The transformation, miniprep and the gel (undigested and digested with the EcoRI and SpeI) worked as expected.


BBa_S03518

Aberdeen_Scotland 2009

The transformation, miniprep and the gel (undigested and digested with the EcoRI and SpeI) worked. Further testings were performed by the formation of the BBa_K182002, PCR analysis, sequencing and everything worked flawlessly according to our expectation.


BBa_I732100

Aberdeen_Scotland 2009

The plasmid miniprep and the gel worked as expected. However, since we did not use this part for our cloning step we cannot comment on the sequencing or the other features of this part.


BBa_R0040

Aberdeen_Scotland 2009

The initial gel worked although the obvious confirmation was not possible due to the very small fragment size (54bp).But later it was confirmed following its usage by forming the part BBa_K182001 through the PCR gel analysis and the sequencing.The plasmid miniprep also worked.

BBa_I13600

Aberdeen_Scotland 2009

The gel analysis and the plasmid miniprep worked quite nicely as expected. But later the construct was further tested and characterised by combining with the bio-brick BBa_K182002 which contained a tet repressor under the control of a CI operator. So, the CFP expression of BBa_I13600was repressed as expected when tested with the BBa_K182002. With the addition of Anhydrotetracycline (an analogue of tetracycline) the CFP expression was restored and this was confirmed performing the fluorescent microscopy assay.

BBa_J37032

Aberdeen_Scotland 2009

Experimental Design
The BioBrick expresses GFP under control of a LuxR responsive promoter. The part was provided by iGEM-HQ, was succesfully mini-preppred and transformed into E.coli. was used to test our constitutive LuxR/LuxI operon (). For that purpose SCS1 E.coli was transformed either with alone (referred to as pIR in figure below), alone, or a combination of both plasmids. The single transformants acted as negative controls.

Results
It would be expected that the transformant would not fluoresce, since it does not express GFP. This was confirmed (top panel, figure below, showing light microscope pictures on the left, and fluorescent images on the right). Similarly, the single transformant was not expected to exhibit much fluorescence, since there is no endogenous expression of LuxR or LuxI in E.coli. A combination of and would be expected to produce high amounts of fluorescence at high cell densities as quorum sensing triggers the Lux promoter of . However, in overnight stationary phase cultures at high density, it was found that the construct expresses the same high amount of GFP fluorescence with or without the presence of LuxR (compare middle panel [J37032 single transformant] with bottom panel [J37032/pIR double transformant])

Conclusion
We conclude that is either not responsive to LuxR, or that the pLux promoter is extremely leaky, driving significant GFP expression in the absence of LuxR. It therefore cannot easily be used to test quorum sensing due to this high background level of GFP expression.

J37TEST figure.jpg



BBa_I732820

BBa_I13601

Aberdeen_Scotland 2009

The gel analysis and the plasmid miniprep worked quite nicely as expected. In addition, the construct was further tested by adding IPTG which took off the lacRepressor of the LacO and hence enabling the CFP expression.


BBa_K081008

BBa_C0051

Aberdeen_Scotland 2009

Our miniprep, double digest and single digest worked as expected. We used this part for further cloning which was successful. The sequencing was correct. However we can not confirm that this part was working as we did not test it's functionality.

BBa_R0062

Aberdeen_Scotland 2009

Our miniprep, digest and gel gave expected results. However we did not use this part for our cloning.

BBa_B0034

Aberdeen_Scotland 2009

Our miniprep, double digest and gel worked properly. We used this part in fusion PCR for building our biobrick. The fusion PCR, cloning and sequence were all correct.

BBa_E0840

Aberdeen_Scotland 2009

Our miniprep, double and single digests worked as expected. We used this biobrick for building two of our parts. We experienced very satisfactory cloning with high efficiency of transformants. The sequencing was correct. We discovered that all the bacteria containing this biobrick were releasing fluorescence even though there was no promoter upstream. The level of fluorescence observed was dependent on the plasmid copy number. We noticed that colonies displayed a visible, yellow-green colour, therefore selection was very easy.

pSB1AC3

Aberdeen_Scotland 2009

The transformation, miniprep and the gel (undigested and digested with the EcoRI and PstI) worked. Further testings were performed by the formation of the and , PCR analysis, sequencing and everything worked as expected.

pSB1AT3

Aberdeen_Scotland 2009

The transformation, miniprep and the gel (undigested and digested with the EcoRI and PstI) worked. Further testings were performed through the PCR analysis and subsequent sequencing.