Difference between revisions of "Team:UGent Belgium/LabNotebook"

• We made a strong expression vector (pXS) by restriction of the linearized plasmid backbone pSB1C3 and insertion of gblock made up of promoter-RBS-cloning site-terminator-terminator (cut with EcoRI and PstI).
• Our first attempts to isolate the inaZ gene from P. syringae and the inaX gene from X. campestris failed.

• We transformed the strong expression vector (cf. 29/08) by electroshock into E. coli TOP10.
• As a backup strategy we also used CPEC with the backbone from the K584027 plasmid to generate a strong expression vector.

• Second attempt to isolate the inaZ gene from P. syringae and the inaX gene from X. campestris. InaX failed, but inaZ was successful.
• Transformation of the strong expression vector by restriction and ligation was not very successful, we only had a few colonies. The backbone amplification using CPEC was successful (cf. 30/08).

• Heatshock transformation of the strong expression vector made with CPEC yielded no colonies.
• Colony PCR on the colonies with the strong expression vector made with restriction and ligation didn’t show any positive ones (cf. 31/08).

Electroshock transformation of the strong expression vector made with CPEC into E. coli TOP10 cells.

• Via colony PCR we saw that all colonies with the strong expression vector made with CPEC and electroshock transformation were all positive (cf. 02/09).
• We transformed E. coli TOP10 cells with our weak expression vector (pXW), which came in today. Q5 CPEC was used for this with the linearized plasmid backbone pSB1C3 and as insert a gBlock consisting of promoter-RBS-cloning site-terminator-terminator. The promoter is weaker than the promoter of the strong expression vector (cf. 29/08).

Colonies from our strong expression vector made with CPEC (cf. 04/09) are cultured and miniprepped. These are used for following constructs:

• pXS-INP_WT using the inaZ PCR fragment
• pXS-INP_NC-mGFPuv
• pXS-INP_NC-Strep (Strep: regular streptavidin)
• pXS-INP_NC-mSA2 (mSA2: monomeric streptavidin)
• pXS-Lpp-ompA-mGFPuv
• pXS-Lpp-ompA-Strep
• pXS-Lpp-ompA-mSA2

We transformed our Golden Gate reactions (cf. 06/08) into E. coli TOP10 cells.

• We did a colony PCR of our weak expression vector (cf. 04/09), and of our constructs made with the strong expression vector (cf. 06/09), both using BioBrick verification primers.
• We tried to make inaZ Golden Gate safe by removing the BsaI sites. To achieve this, the gene is cut into 3 fragments. The combined fragments however did not show the correct length.

The colony PCR of E. coli cells with the constructs with the strong expression vector showed no positive colonies (cf. 06/09). The colony PCR on our cells transformed with the weak expression vector (cf. 04/09), however, did. We therefore tried cloning all our parts into the weak expression vector by using a Golden Gate reaction mix. These Golden Gate reactions were then transformed into E. coli TOP10 cells. Incubation was done at 30°C instead of 37°C to repress the plasmid copy number

• We got our sequencing results: the strong expression vector is good!
• Colonies with the weak expression vector constructs are still too small to pick up with colony PCR (cf. 09/09)

• All our plates with the weak expression vector constructs show colonies! Fluorescence is seen for the pXW-INP_NC-mGFPuv construct. All Lpp-ompA plates have a mixed phenotype, and colony PCR was performed to proof that the small colonies are the positives ones, the larger ones the negative ones.
• We performed PCR to create following constructs:
  • pXW-Lpp-ompA-mGFPuv-(m)Strep using Lpp-ompA-mGFPuv fragment
  • pXW-mGFPuv-m(Strep) using mGFP
  • pXS-mGFPuv using mGFP
  We also repeated previous PCR (cf. 08/09) of the largest piece of inaZ to make it Golden Gate safe.

• Miniprep of a number of colony PCR positive colonies (cf. 09/09).
• Golden Gate assemblies of:
  • pXW-inaZ_GGsafe
  • pXW-mGFPuv-Strep
  • pXW-mGFPuv-mSA2
  • pXW-mGFPuv
  • pXS-mGFPuv

• pXW-Lpp-ompA-mGFPuv miniprep tubes that did not grow yesterday did show growth today, probably through mutations.
• Transformed golden gate assemblies (cf. 12/09) into E. coli TOP10 cells.

Colony PCR of the Golden Gate assemblies (cf. 12/09): fail for pXW-INP_GGsafe, okay for other assemblies

Colony PCR screening of 8 more colonies with pXW-inaZ_GGsafe showed no result (cf. 13/09)

• Minipreps of the following plasmids and sequencing with verification primers:
  • pXW-mGFPuv-Strep
  • pXW-mGFPuv-mSA2
  • pXW-mGFPuv
  • pXS-mGFPuv
• We did a PCR to go from high copy to low copy (LC) backbone, with as backbone pSB3K3 and 4 inserts: INP_NC-Strep, INP_NC-mSA2, Lpp-ompA-Strep and Lpp-ompA-mSA2. The backbone and Lpp-ompA-mSA2 both failed.

• We retried the PCR to go from high to low copy backbone, with new primers for the pSB3K3 backbone, but this again failed. The Lpp-ompA-mSA2 insert was also redone with now the Golden Gate mix as template, which was successful.
• Golden gate assembly of pXW-inaZ_GGsafe.

• We did a colony PCR for the Golden Gate assembly of pXW-inaZ_GGsafe (cf. 19/09).
• We opted for a new backbone for the low copy vector (cf. 19/09): pSC101-Kan vector.

• We digested some colony PCR samples (cf. 21/09), and controlled them with BsaI. If pXW-inaZ_GGsafe is indeed Golden Gate safe, it should not be cut. This was okay for two colonies! These colonies are plasmid prepped for sequencing.
• We again retried the PCR to go from high to low copy backbone.For this, we used pSC101 as backbone. A new Lpp-ompA-mSA2 insert was also done, with again the Golden Gate mix as template. A weak expression vector with an empty expression site was also added.

CPEC assemblies to create:

• pLC-XW
• pLC-XW-INP_NC-Strep
• pLC-XW-INP_NC-mSA2
• pLC-XW-Lpp-ompA-Strep
• pLC-XW-Lpp-ompA-mSA2
• pSB1C3-mSA2

Colony PCR of all CPEC assemblies (cf. 26/09).

Second attempt for CPEC assemblies (cf. 26/09), with increased backbone DNA and an altered backbone/insert ratio.