Team:Paris Bettencourt/Notebook/Phage Sensor/Saturday 7th September.html


Phage Sensor

Saturday 7th September

Ligation, Making Electrocompetent Cells, Gibson Assembly, Transformation, Liquid culture of E1010


Reagent Volume
Vector 1 µl
Insert 3 µl
H2O 4.5 µl
Fermentas T4 Ligase Buffer 1
Fermentas T4 Ligase Enzyme 0.5
Total Volume 10 µl

SPCR11, pSB1A3, pSB1C3
SPCR13, pSB1A3, pSB1C3
SPCR2, pSB1A3, pSB1C3

Incubate at room temperature for 10 minutes.

Making Electrocompetent Cells
1) Start a liquid culture of cells.
NEB turbo
2) dilute the cells 100X.
100 ml LB.
Grow at 30°C for about 90 minutes.
3) Harvest the cells.
When the cells reach an OD600 of between 0.6 and 0.8
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.
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.

Gibson Assembly

Amount per Reaction
Positive Control**

PCR Fragment(s)
+ linearized vector
2-10 μl (0.02–0.5 pmols)*

Assembly Master
Mix (2X)
10 μl

Deionized H2O
XX μl

Total Volume
20 μl

Incubate samples in a thermocycler at 50°C for 15 minutes.
Put on Ice

Transformation pS002 (Chl), pS002 (Amp), pS003 (Amp), pS004 (Chl), pS004 (Amp), pS005 (Chl), pS006-7 (Chl), pS007 (Chl), pS008 (Amp), pS009 (Chl), pS012 (Amp), pS013 (Chl), pS013 (Amp)

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 1/2 h at 37 °C with shaking.

9) Plate 10/200 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.

Liquid culture of E1010