Team:Grenoble/Biology/Notebook/June/week 28

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iGEM Grenoble 2012

Project
week 27 week 28 week 29 week 30

Week 28: July 09th to July 15th

Goal of the week

we wanted to recover and amplify the biobricks involved in our genetic networks:
  • pAra/Bad_RBS_GFP (1300bp)
  • RBS_Cya (2600bp)
  • pLAC (100bp)
  • fha (80bp)
  • eCFP (800bp)
  • pLAC_RBS (120bp)
  • RsmA (200bp)
  • rsmY (170bp)
  • pSB1A3 (2400bp)
  • pSB4K5 (2400bp)
  • pSB3C5 (2400bp)
We also planned to realise the gibson assemblies for the first constructions.

Monday, July 09th:

Precultured cells are prepared:
  • Strains = BW25113 WT and BW25113 cya- pAra/Bad
  • Conditions = LB liquid medium, 37°C, 200rpm, overnight

Tuesday, July 10th:

For the PCRs, we changed the enzyme from GoTaq to High Fidelity (HF) Phusion.
We did some colony PCR with a HF Phusion enzyme (protocol) to amplify:
  • fha1, RsmA, rsmY and pSB1A3 from iGEM Grenoble 2011 glycerol stock.
  • pAra/Bad_RBS_GFP from BW25113 cya- pAra/Bad precultured cells.
  • RBS_Cya from BW25113 WT precultured cells.
We did the PCR both with and without DMSO (Amplification of difficult targets, such as those with GC-rich sequences or secondary structure, may be improved by the presence of additives such as DMSO).

To separate the PCR products, we prepared two gels:
  • a 1.3% TAE agarose gel, for the small fragments: RsmA, fha1 and rsmY (length < 1000bp)
  • a 0.8% TAE agarose gel, for the big fragments: pSB1A3, RBS_Cya, and pAra/Bad_RBS_GFP (length > 1000bp)

Migration conditions = 50V during 1h15.
We used EtBr to reveal the DNA fragments.
photo_gel_4
Migration result for the 1.3% TAE agarose gel (small fragments)
(the DNA ladder scale is in kb)
Lane 1: DNA ladder 100bp (biolabs)
Lane 2 and 3: fha1 PCR product
Lane 4 and 5: RsmA PCR product
Lane 6 and 7: rsmY PCR product
Lane 8 and 9: fha1 PCR product (DMSO)
Lane 10 and 11: RsmA PCR product (DMSO)
Lane 12: rsmY PCR product (DMSO)
Lane 13: DNA ladder 100bp (biolabs)

photo_gel_5
Migration result for the 0.8% TAE agarose gel (big fragments)
(the DNA ladder scale is in kb)
Lane 1: DNA ladder 1kb (biolabs)
Lane 2 and 3: RBS_Cya PCR product
Lane 4 and 5: pSB1A3 PCR product
Lane 6 and 7: pAra/Bad_RBS_GFP PCR product
Lane 8 and 9: RBS_Cya PCR product (DMSO)
Lane 10 and 11: pSBA13 PCR product (DMSO)
Lane 12: pAra/Bad_GFP PCR product (DMSO)
Lane 13: DNA ladder 1kb (biolabs)

There was a migration problem on the second gel (DNA ladder migration was not right) and we only saw primer dimer bands. There was a PCR condition problem.

Precultured cells were prepared:
  • Strains = BW25113 WT.
  • Conditions = LB liquid medium, 37°C, 200rpm, overnight.

Wednesday, July 11th:

We did a miniprep (protocol kit: Nucleospin plasmid Quick Pure) on three iGEM Grenoble 2011 strains:
  • fha1
  • RsmA
  • rsmY

We did a 15min digestion (protocol) by some restriction enzymes (XbaI and PstI) in order to check if there were the right plasmids in the strains.

To separate the digestion products, we prepared a 1.3% TAE agarose gel.
Migration conditions = 50V during 1h15.
In order to reveal the DNA fragments, we used EtBr.
photo_gel_6
Migration result for a 1.3% TAE agarose gel
(the DNA ladder scale is in kb)
Lane 1: DNA ladder 100pb (biolabs)
Lane 2 and 3: fha1 digestion product (XbaI)
Lane 4 and 5: RsmA digestion product (XbaI)
Lane 6 and 7: rsmY digestion product (XbaI)
Lane 8 and 9: fha digestion product (pSTI)
Lane 10 and 11: RsmA digestion product (pSTI)
Lane 12 and 13: rsmY digestion product (pSTI)
Lane 14 and 15: fha1 digestion product (XbaI-pSTI)
Lane 16 and 17: RsmA digestion product (XbaI-pSTI)
Lane 18 and 19: rsmY digestion product (XbaI-pSTI)
Lane 20: DNA ladder 100pb (biolabs)

We seen the DNA bands were at the wrong position, like there was no digestion. We thought the digestion problem occured during the heating step (we had a problem using the thermoblock).

Using iGEM 2012 biobricks we transformed (protocol) BW25113 WT cells. We obtained five transformed strains with five different biobricks:
  • BBa_I13601: pLAC_RBS
  • BBa_E0422: eCFP
  • pSB3C5 plasmid
  • psB4K5 plasmid
  • psB1A3 plasmid
Precultured cells were prepared:
  • Strains = BW25113 cya- pAra/Bad.
  • Conditions = LB liquid medium, 37°C, 200rpm, overnight.