Team:Paris Bettencourt/Notebook/Phage Sensor/Wednesday 21st August.html

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Phage Sensor

Wednesday 21st August

Gradient PCR SPCR5, SPCR6, M13 Test, Electrocompetent Cells (sSP017-XL-1 Blue, Litmus 28i), Transformation

Gradient PCR SPCR5, SPCR6

ReagentVolume
1x
Nuclease-free water37,25µL
5x Phusion HF Buffer10µL
10 mM dNTPs1µL
Forward Primer (10 µM)0.5µL
Reverse Primer (10 µM)0.5µL
Template Plasmid0.25µL
Phusion DNA Polymerase0.5µL
Total Volume50µL


Gradient:
Pos 1: 40.1°
Pos 2: 40,8°
Pos 3: 42.2°
Pos 4: 44.2°
Pos 5: 46.7°
Pos 6: 49.4°
Pos 7: 52.1°
Pos 8: 54.7°
Pos 9: 57.1°
Pos 10: 59.0°
Pos 11: 60.2°C

M13 Test
Liquid cultures of sSP012 and sSP020
1) 100 μ l of plating bacteria per tube
2) Prepare tenfold serial dilutions (10-6 to 10-9 ) of the bacteriophage stock in LB
3) Put 10 μ l/ 100 μ l of each dilution to the bacteria
4) Mix the bacteriophage particles with the bacterial culture by vortexing gently.
5) Add 40 μ l of X-gal solution (working conc) and IPTG (working conc) solution to each of the tubes
6) Add 3ml of Agar to each tube and gently vortexing for 3 seconds
7) Pour the mixture onto plates containing LB medium supplemented with 5 mM MgCl2
8) Swirl the plate gently to ensure an even distribution of bacteria and agar.
9) Incubate them at 37°C.


Electrocompetent Cells (sSP017-XL-1 Blue, Litmus 28i)
1) The night before the transformation, start an overnight culture of cells.
sSP017 (XL1 Blue Litmus 28i)
2) The day of the transformation, dilute the cells 100X.
100 ml LB Amp.
Grow at 30°C for about 90 minutes.
3) When the cells reach an OD600 of 0.2.
4) Harvest the cells.
When the cells reach an OD600 of between 0.6 and 0.8 (OD: 0,683)
Split the culture into 2x 50 ml falcon tubes, on ice.
Centrifuge at 4 °C for 10 min at 4000 rpm.
5) Wash and combine the cells.
Remove the supernatant.
Resuspend the cells in 2x 25 ml of ice cold water.
Combine the volumes in a single 50 ml falcon tube.
6) Wash the cells 2 more times.
Centrifuge at 4 °C for 10 min at 4000 rpm.
Resuspend in 50 ml of ice cold water.
Repeat.
7) Wash and concentrate the cells for electroporation.
Centrifuge at 4 °C for 10 min at 4000 rpm.
Resuspend in 1-2 ml of ice cold water.
We will use 200 ul of washed cells per transformation.

Transforming pKD13 into pir+ E.coli
1) Prepare BD tubes with a pipette filled with LB at the interior of each tube (pipette supplied with the electroporation cuvette)

2) Test the purity of the electrocompetent cells.
Add 200 ul of washed cells to a cuvette.

3) Mix the cells and DNA in a cuvette.
200 ul of washed cells with 200 ng of PCR product.
Keep the cuvette on ice until just before the electroporation.

4) Preload a pipette with 1 ml of LB.

5) Pulse the cuvette with voltage.
Dry the electrodes with a kimwipe prior to loading.
Use the EC2 setting.

6) Listen for arcing.
A cracking sound means all the cells are dead.
Note the time constant: 5 is good, 5.8 is great.

7) Immediately recover the cells.
Add the 1 ml of preloaded LB and pipet up and down to mix.
Collect 1 ml of cells, some volume is lost in the cuvette.

8) Incubate 2 h at 37 °C with shaking.

9) Plate 100 ul of recovered cells on selective plates.
Use antibiotic appropriate to the part being integrated.
Let the other 900 ul rest overnight at room temperature.

10) Concentrate and plate the remaining cells
Spin down quickly and resuspend in 100 ul LB before plating.

Transformed cells should be incubated at 37 °C.
Colonies should appear 24-48 h after plating.