Team:Paris Saclay/Notebook/July/12

Tuesday 12th July

Bringing DNA closer

Amplification of DS-TDcasN-, DS-SPcasN- and pZA21 plasmids

By Caroline

Plasmids extracted the 4/07/16 were used to amplify the dCas9 needed for the bring DNA closer tool and the pZA21 plasmid in which the tool will be inserted. A PCR was carried out using Q5® High-Fidelity 2X Master Mix and following the usual protocol adapted to have 50µL at the end.

Electrophoresis of the PCR amplification

By Caroline

5µL of the amplifications are mixed with 1µL of purple loading dye. The solutions are put into a 0.8% agarose gel and migrated for 30min.

Migration of SP, TD and pZA21

Liquid culture of transformed NM, TD, ST1 and SP dcas9

By Mathilde and Laetitia

Two colonies from each Petri dishe was incubated in 1mL of LB and Spectinomycin (50µg/mL). Our 8 cultures were put in incubation at 37°c, 180 rpm ON.

Biobrick characterization

Electrocompetents and transformation by electroporation of BL21

By Charlene

Cells transformed on 11/07/16 grew overnight. However no colony was observed. In order to control if there is any bacteria transformed but not among what was spread on Petri dish, we redo the experiment. 100 µL (500µL concentrated) of transformed bacteria for each condition, conserved at -4°C from yesterday, were split in 3 solutions :

  • 30µL of bacteria + 3mL LB + Streptomycin (50µg/mL) + Chloramphenicol (30µg/mL)
  • 30µL of bacteria + 3mL LB + Streptomycin (50µg/mL)
  • 30µL of bacteria + 3mL LB + Chloramphenicol (30µg/mL)

Cells were incubated for 8h at 37°C, 200rpm.

No bacteria grew so we concluded that there was a problem with the transformation.

Visualization

Transformation of gBlocks 4.2 pPS16_008

By Laetitia and Mathilde

DH5α heat-shock competent cells were transformed with plasmid pPS16_008 (gBlock 4.2).

Petri dishes peparation (x3) :

  • 10µL of Ampicillin (50µg/mL)
  • 5µL of Xgal (0.25µL/mL)
  • 2µL of IPTG (0.1µL/mL)
  • 20mL of LB+Agar

Cells transformed with the two gBlocks constructions were spread on Petri dishes in duplicata (50µL and 150µL) and a control construct was also spread. The plates were put in incubation at 37°c overnight.

High fidelity PCR on bacteria transformed with pPS16_004 and pPS16_007

By Alice

A PCR with Q5® High-Fidelity 2X Master Mix was performed on clones selected after screening PCR of the 11/07/16, following this protocol.1151_pheoR and 1152_pheoF primers were used. Annealing temperature was 60°C. After amplification, 1 µL of loading dye was added to 5µL of each PCR products. Then 5 µL of this mix were put on gel. PCR products were migrated 30min at 100V.

PCR products expected were :

Plasmids Band size (bp)
pPS16_004 865
pPS16_007 763

No PCR products were observed. The reason remains a mystery.

gBlock sequencing

By Caroline

PCR products obtained 11/07/16 : pPS16_001, pPS16_002, pPS16_003, pPS16_005,pPS16_006, pPS16_007, pPS16_008 and pPS16_009 were sent to sequencing.