Team:Marburg/Labbook/CDI
15/05/18
PCR
| PCR | PCR Mix 1 | PCR Mix 2 |
| GXL buffer | 10 uL | 10 uL |
| dNTPs (from GXL kit | 4 uL | 4 uL |
| GXL polymerase | 2uL | 2uL |
| ICD001 (10 uM) | 0.5uL | 1uL |
| ICD007/ICD008 (10 uM) | 0.5uL | 1uL |
| EC93 genomic DNA (15 ng/uL) | 0.5 uL | 1 uL |
| ddH2O | 32.5uL | 29.5uL |
| Program | time |
| Start cycle (30x) | |
| 98 °C | 10 s |
| 60 °C | 15 s |
| 68 °C | 2 min |
| close cycle | |
| 8 °C | store |
Ran of analytical gel. No bands were observed.
15/05/19
PCR
Bands visible! Lanes 1 and 2 right of the ladder should have a 10506 bp band. Lanes 3 and 4 right of the ladder should have a 11414 bp band (gel description should read EC93 instead of EC90).
PCR cleanup (according to Thermo Scientific protocol), elution in 21 ul.
Concentrations according to Nanodrop: EC93 w/ 001+007: 92 ng/ul; EC93 w/ 001+008: 57 ng/ul
15/05/21
PCR
Primers ICD014 and ICD015 arrived! These will be used to amplify the Pick up backbone with overlaps for the full-length Cdi operon. PCR should yield a 3391 bp fragment.
| PCR | PCR Mix 1 |
| GXL buffer | 10 uL |
| dNTPs (from GXL kit | 4 uL |
| GXL polymerase | 2uL |
| ICD0014 (10 uM) | 1 uL |
| ICD0015 (10 uM) | 1uL |
| 1:10 diluted plasmid X | 1 uL |
| ddH2O | 31 uL |
| Program | time |
| Start cycle (30x) | |
| 98 °C | 10 s |
| 60 °C | 15 s |
| 68 °C | 35 s |
| close cycle | |
| 8 °C | store |
Turned out that the template was wrong. Inoculated 3 ml LB+chloramphenicol for overnight culture of correct Curly clone (clone No. 3) for Miniprep tomorrow.
15/05/22
PCR, Gibson Assembly and Transformation
Miniprep of 1.5 ml of Curly clone No. 3 according to Thermo Scientific Protocol.
PCR with primers ICD014 and ICD015 and freshly prepped Curly plasmid to amplify the backbone for the CDI plasmid (pICD001).
Reaction mix and PCR program see 15-05-21.
Analytical gel: Correct size! (3391 bp)
Gibson assembly of Curly plasmid/ICD014+015 PCR fragment and CDI operon (EC93 genomic DNA with ICD001 +008)
G.A. reaction mix:
| Gibson mix | volume |
| Insert | 2.65ul (= 151ng = 0.02 pmol) |
| Backbone | 0.54ul (= 45ng = 0.02 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 6.81 uL |
| temperature | time |
| 50 °C | 15 min |
| 16 °C | store |
• Thaw NEB turbo cells on ice
• Dilute G.A. mix 1:3 (5ul mix + 10ul ddH2O)
• Add 2ul of dilution to 25ul of NEB turbo cells
• Transfer the cells to electroporation cuvette
• Electroporate and add 975ul SOC medium immediately
• Recover 1h at 37°C
• Spin down briefly and discard supernatant
• Plate on chloramphenicol plate
15/05/26
PCR, Gibson Assembly and Transformation
On 15-05-22 DpnI digestion has been forgotten, so the transformed cells probably carry the Curly plasmid instead of the Gibson assembly product. So we repeated the procedure including DpnI digestion.
PCR of Curly backbone: See 15-05-21
DpnI digestion program:
| temperature | time |
| 37 °C | 30 min |
| 16 °C | store |
Gibson assembly of Curly plasmid/ICD014+015 PCR fragment and CDI operon (EC93 genomic DNA with ICD001 +008) G.A. reaction mix:
| Gibson mix | volume |
| Insert | 2.65ul (= 151ng = 0.02 pmol) |
| Backbone | 0.51ul (= 45ng = 0.02 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 6.84 uL |
| temperature | time |
| 50 °C | 15 min |
| 16 °C | store |
• Thaw NEB turbo cells on ice
• Add 2ul of Gibson assembly product to25ul of NEB turbo cells
• Transfer the cells to electroporation cuvette
• Electroporate and add 975ul SOC medium immediately
• Recover 1h at 37°C
• Spin down briefly and discard supernatant
• Plate on chloramphenicol plate (300µL of 0,4% Glucose added to the plate to reduce transcription of Lac promoter)
Gibson mix was not diluted 1:3 in contrast to first attempt on 15-05-22
15/05/27
Plasmidisolation
Colonies are grown wich hopefully carry CDI plasmid. To check this, 12 colonies have been picked and cultivated in 3mL LB broth with additional 0.4% glucose.
In the evening, 1.5ml of cell suspension were pelleted and Miniprep was carried out with the Qiagen Robot.
15/05/28
Plasmidisolation, SacI Digest
The concentration of all the 12 colonies was measured and noted as follows:
| plasmid | concentration ng/uL |
| #1 | 77 |
| #2 | 30 |
| #3 | 90 |
| #4 | 88 |
| #5 | 88 |
| #6 | 86 |
| #7 | 97 |
| #8 | 74 |
| #9 | 84 |
| #10 | 88 |
| #11 | 62 |
| #12 | 81 |
| Digest | volume |
| DNA template | 10 uL |
| Cutsmart buffer | 2 uL |
| Distilled water | 7 uL |
| SacI | 1 uL |
| total | 20 uL |
Analytic gel ; correct size abt 6700 and 8000
The DNA sample was send to determine the sequence and it was positive. We actually got the sequence which we expected.
15/05/31
Overnightcultures
Inoculation of
• four BBa_I13522 (GFP) clones in 3ml LB+CAM overnight
• Olga's W3110 strain with integrated RFP and Kann resistance in 3ml LB+Kann
• W3110 wildtype in 3 ml LB as host for our GFP construct
15/06/1
Transformation into chem. comp. cells
Plasmid purification (four BBa_I13522 (GFP)) was realized using the "Thermo Scientific GeneJET Plasmid Miniprep Kit"
Tansformation:
GFP_1 Plasmid into E.coli (strain W3110)
pICD001-1 Plasmid into E.coli (strain W3110 with integrated RFP)
pICD001-3 Plasmid into E.coli (strain W3110 with integrated RFP)
Transformation protocol:
1. Dilute 1:100 overnight culture (Max 15-05-31)
2. Grow 10 mL day culture (2.5 h) at 37 °C
3. Take 1 mL, spin down full speed (1 min, 17.000 rpm), put on ice
4. Add to pellet 100 micro liter of TSS, resuspend on ice.
5. Add 1 micro liter of Plasmid (GFP_1 ; CDI_1; CDI_3)
6. Incubate 45 Min on ice
7. Put at 42 °C for 1 min.
8. Incubate 15 min on ice
9. Add 1 mL LB Medium with 0.4 % Glucose, resuspend, incubate 2 h incubator at 37 °C, 220 rpm
10. Spin down, resuspend in 50 micro liter residual media, plate on LB-Kann, incubate at 37 °C over night (step 10 done by Max)
15/06/2
Sequencing results
Colonies on all three transformation plates!
- GFP plasmid (BBa_I13522): Colonies beyond count
- pICD001-1 Plasmid into E.coli (strain W3110 with integrated RFP): 23 colonies
- pICD001-3 Plasmid into E.coli (strain W3110 with integrated RFP): 26 colonies
As a result, the W3110/RFP strain transformed with pICD001-1 will become strain CDI002 (a.k.a. the killer strain). The W3110 wildtype transformed with the GFP plasmid (BBa_I13522) will become strain CDI003 (a.k.a. the Opfer strain).
Inoculation of CDI002 and CDI003 in 3 ml LB CAM +1%glucose
15/06/3
IPTG dose response
Dose-response curve of CDI002 at different induction levels --> if Cdi operon is expressed, we expect a higher metabolic burden at high induction compared to low induction. The used broth was LB with 1:1000 Chloramphenicol and 1 % glucose.
The concentrations of IPTG were gained by dilution series.
15/06/5
IPTG dose response, killing assay
Repetition of Dose-response assay with higher IPTG concentrations. At first the overnight cultures of 4 strains (W3310, W3310-RFP, CDI 002, CDI 003) were diluted to an OD600 of 0,08 to a volume of 10mL LB-medium
• Flask with CDI003 with 1,6µM IPTG fell over. So last measurement was after 190min.
• CDI003 (GFP strain) grew fast at the beginning. After 3,5h the cells clumped together and the medium cleared up.
• The influence of different IPTG concentrations on the growth rate is very low but a slight trend is noticable.
Preparing of daycultures for flow cytometry in different broths.
Broths:
LB = LB-medium with 0.8 mM IPTG
LB-CAM = LB-medium with 0.8 mM IPTG and 1:1000 Chloramphenicol
| culture (broth, Time [min] | 0 min | 60 min | 90 min |
| LB, W3110 RFP | 0.1 | 0.25 | 0.4 |
| LB, W3110 | 0.1 | 0.41 | 0.7 |
| LB-CAM, CDI002 | 0.1 | 0.21 | 0.46 |
| LB-CAM, CDI003 | 0.1 | 0.32 | 0.59 |
| LB,CDI002 | 0.1 | 0.23 | 0.45 |
| LB,CDI003 | 0.1 | 0.31 | 0.65 |
Different cultures were mixed (2 mL/ 2mL) to a total volume of 4 mL, incubated at 37 °C, 250 rpm for 3 hours. An Aliqout of 0.5 mL was mesured every 60 Minutes.
| number | mixed cultures | ratio | broth |
| 1 | CDU002+CDI003 | 1:10 | LB |
| 2 | CDU002+CDI003 | 1:1 | LB |
| 3 | CDU002+CDI003 | 10:1 | LB |
| 4 | CDU002+CDI003 | 1:10 | LB-CAM |
| 5 | CDU002+CDI003 | 1:1 | LB-CAM |
| 6 | CDU002+CDI003 | 10:1 | LB-CAM |
| 7 | W3110 RFP+CDI003 | 1:10 | LB |
| 8 | W3110 RFP+CDI003 | 1:1 | LB |
| 9 | W3110 RFP+CDI003 | 10:1 | LB |
| 10 | Control CDI002 only | LB | |
| 11 | Control CDI003 only | LB | |
| 12 | Control W3110 | LB | |
| 13 | Control W3110 RFP | LB | |
| 14 | Control CDI002 only | LB-CAM |
The victim strain CDI003 is overgrown by CDI002, but also does the W3110 RFP strain.
The victim strain CDI003 starts shrinking after reaching of an OD-600 of 1.2.
Aggregates in samples 1,7,11 and 8
Optical whitening in samples 11 and 12
FACS results (data not shown) were not as expected so we will repeat the experiment.
Experiment will be repeated with changed parameters: lower density, lower flowrate, other broth, change of intensity, change of voltage, different FACS parameters.
15/06/9
PCR, DpnI Digest, Overnightcultures
PCR of pCDI001 (full length CDI operon) with Primers iCD003 and iCD007. Result is linearised plasmid withour CdiA-CT and CdiI.
PCR progam and Mix with GXL Polymerase are listed in the protocol section.
Inoculation of 10 W3110-RFP clones in 3 ml LB over night to check with FACS the next day (last FACS measurement showed three populations in mCherry histogram. We wanted to check, if this is clone-specific or the same for different clones).
Inoculation of W3110-WT, W3110-RFP, CDI002 and CDI003 in 3 ml LB and TB to compare overnight growth tomorrow.
15/06/10
PCR Purfication, Bluntend cloning
Sample Purification
The Sample DNA was purified with the purification kit of GeneJET PCR
to the 49ul volume of sample was added 49ul of binding puffer, mixed, centrifugated, 700ul wash Buffer added ,centrifugated for one minute twice to assure the removal of any residual of wash buffer.
50ul Elution Buffer was then added to the column containing the DNA sample and centrifuged. A concentration of 65,51ug/ml was measured at the nanodrop.
Blunt-end cloning
Blunt-end cloning of the purified PCR fragment was done as follows and at 37°C incubated for 30 min
17ul sample DNA
2ul T4 Ligase Puffer
1ul Kinase (T4-PNK)
20min inactivation of T4-PNK at 65°C
Made LB plates with CAM and 0.8 mM IPTG
| strain | LB media | TB media |
| W3110-WT | 6.6 | 3.1 |
| W3110-RFP | 5.8 | 2.8 |
| CDI002 | 4.1 | 1.9 |
| CDI003 | 4.1 | 1.4 |
-> Strains harboring a high copy plasmid (CDI002 and 003) grow only half to 2/3rd as dense as strains without plasmid
FACS result of yesterday's o.n. cultures: All show the high mCherry peak in histogram, not the intermediate one or the "negative" peak. The occurence of different mCherry populations seems to be cell cycle specific and not clone-specific.
15/06/11
swarming assay; Transformation
To get a better negative control than the W3110-RFP for our swarming plates and flow cytometry mesurements, we transformed blunt-end-cloned fragment (plasmid without CdiA-CT and CdiI (pICD002)) (made by Daniel 15-6-09) into W3110-RFP strain.
Following Protocol was used:
Transformation of non-competent E.coli cells
To see how much Plasmid we need to get colonies on LB+CAM plates we used different amounts of Plasmid for the Transformation Protocol.
- 1. 0.1 µL Plasmid pCDI001 without CdiA-CT and CdiI (pICD002)
- 2. 1 µL Plasmid pCDI001 without CdiA-CT and CdiI (pICD002)
- 3. 10 µL Plasmid pCDI001 without CdiA-CT and CdiI (pICD002)
15/06/12
swarming assay; Transformation
On all LB+CAM plates colonies were observed. Most colonies resulted from the third Transformation with 10 µL Plasmid.
Six colonies were picked for overnight cultures to perform Miniprep the next day.
Swarming assay
A swarming assay was performed to check if growth inhibition can be proven. LB-Plates (CAM, 0.8mM IPTG) with 0,27% Agar were used to give the bacteria the possibility to swarm across the plate.
After 3 days incubation at 30°C the plates were put on a blue light screen to visualise fluorescence.
15/06/13
Plasmid isolation
Miniprep of the six pICD002 candidates according to Thermo Scientific protocol.Undigested pICD002 candidates ran on analytical gel
15/06/16
Overnight cultures, sequencing
Overnight cultures of CDI002, CDI003, W3110, NEBTurbo with pICD001Plate CDI002, CDI003 and CDI004 each on a third of a LB-Plate
Sent pICD002-1 and pICD002-6 for sequencing with reverse primer 160 that binds downstream of CdiI and the CdiA-CT that we want to kick out.
15/06/17
growth analysis, SDS-Page
Diluting of all overnight cultures to an OD600 of 0,05 to start a day culture OD600 with time:| strain | T 0 | 2 hours | 5 hours |
| W3110 | 0.05 | 0.69 | 3.1 |
| CDI002 | 0.05 | 0.10 | 0.20 |
| CDI003 | 0.05 | 0.07 | 0.17 |
| CDI004 | 0.05 | 0.14 | 0.64 |
Day cultures are diluted 1:100 and plated on LB-Agar plates to have single colonies on the plates.
SDS-PAGE was started to see if CdiA, CdiB and CdiI are expressed. All steps are done with CDI002 and W3110 as control. Sepperating gel:
| Chemicals | volume | volume |
| Acrylamide percentage | 6 | 15 |
| water | 5.2 mL | 2.2 mL |
| Acrylamide_Bis-acrylamide (30%;0.8%) | 2 mL | 5 mL |
| 1.5M Tris (pH=8.8) | 2.6 mL | 2.6 mL |
| 10% SDS | 0.1 mL | 0.1 mL |
| 10% ammoniumpersulfat | 0.1 mL | 0.1 mL |
| TEMED | 0.01 mL | 0.01 mL |
| Chemicals | volume |
| water | 2.975 mL |
| 0.5 M Tris-HCl, pH6.8 | 1.25 mL |
| 10% SDS | 0.05 mL |
| Acrylamide/Bis-acrylamide (30%; 0.8%) | 0.67 mL |
| 10% Ammoniumpersulfat | 0.05 mL |
| TEMED | 0.005 mL |
1mL of cells are centrifuged and supernatant is discarded.
Cells were prepared in different ways:
- 1. Pellet is resuspended in 50µL of sample buffer.
Samples are mixed by pipetting up and down for 2 minutes to break CDI A if present on the surface of the cell, suspension is centrifugated and supernatant is used for gel - 2. Cells are used whole.
65µL of sample buffer is used to resuspend the pellet, cells are incubated for 10 minutes at 96°C, centrifugation for 3 minutes at max speed. - 3. Cells 50µL of lysis buffer is used to resuspend the pellet, 2µL of protease inhibitor is added, incubation at room temperature for 10 minutes to lyse the cells, centrifugation for 10 minutes at max speed and 4°C
- a. Supernatant is used with 16µL SDS-buffer
- b. Pellet is used with 65µL sample buffer
Sequencing results of pICD002-1 and pICD002-6: Nice sequence up to the blunt-end cloning site! Then multiple sequences seem to overlap. Cloning needs to be repeated!
15/06/18
growth analysis, SDS-Page
Repeated the PCR for pICD001 backbone without CdiA-CT and CdiI (see 15-06-09) and ran analytical gel:
(This time DpnI was heat inactivated, just to be sure that it does not interfere with the following steps)
PCR cleanup using Thermo Scientific Cleanup kit. We eluted in 30 ul pre-warmed elution buffer (recommended for fragments >10 kb).
Nanodrop: 99ng/ul DNA
15/06/19
blunt end cloning; ligation
5'-phosphorylation of PCR fragment with polynucleotide kinase (for subsequent blunt-end cloning). PNK mix:| Chemicals | volume |
| DNA template | 17 uL (0.184 pmol) |
| T4 DNA ligase buffer | 2 uL |
| PNK | 1 uL |
| temperature | time |
| 37 °C | 30 min |
| 65 °C | 20 min |
| chemicals | volume |
| ddH20 | 14.44 uL |
| PNK mix | 2.56 uL |
| T4 DNA ligase buffer | 2 uL |
| T4 DNA ligase | 1 uL |
| temperature | time |
| RT | 2 h |
| 65 °C | 10 min |
15/06/24
plasmidisolation; Digest
Miniprep of the six pICD002 candidates according to Thermo Scientific protocol. Elution in 30µL elution bufferWe wanted to check if all pICD002 candidates got the right plasmid formation. So we did an Restriction assay with the six pICD002 candidates:
| Restriction assay | pICD002_1 | pICD002_2 | pICD002_3 | pICD002_4 | pICD002_5 | pICD002_6 |
| DNA | 1.35 mL | 1.63 mL | 3.33 mL | 2.77 mL | 2.13 mL | 1.36 mL |
| NEB: cutsmart buffer | 2 mL | 2 mL | 2 mL | 2 mL | 2 mL | 2 mL |
| BSTZ17I (restriction enzym) | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL |
| EcoRI (restriction enzym) | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL | 0.5 mL |
| water | 15.65 mL | 15.37 mL | 13.67 mL | 14.23 mL | 14.87 mL | 15.64 mL |
Volume: 15 µL
100 ng DNA/µL
2 µL pICD002_X (1 and 6)
2µL Primer
11 µL Water
15/06/25
growth experiment
Due to our results this far we decided to go mesure a new growth curve (OD600 ) with CDI001 (W3110 + pCDI001) and W3110: used browth: LB + 0.2 % Glucose and Chloramphenicol for CDI001 to hold the selection pressure| time/strain | W3110 | CDI001 |
| 0 min | 0.1 | 0.1 |
| 40 min | 0.2 | 0.12 |
| 90 min | 0.71 | 0.18 |
| 120 min | 1.13 | 0.24 |
| 180 min | 1.0 | 0.43 |
| 230 min | 1.1 | 0.72 |
| 270 min | 1.0 | 1.0 |
| 320 min | 1.2 | 0.6 |
| 360 min | 1.2 | 0.43 |
| 420 min | 1.2 | 0.43 |
| 480 min | 1.3 | 0.44 |
After 270 minutes we add IPTG to a total concentration of 0.5 mM (flask with CDI001)
After an OD-600 of 1.0 was observed we aliqout the equivalent of 1 mL of cells at OD600 = 1.0 in a 1.5 mL microfuge tube (t=0)
Next step was induction with IPTG (0.5 mM) and continued shaking at 250 rpm for serveral hours
Aliquots were extracted every hour.
SDS Gel data here not shown.Growth of strains harboring plasmids is still very poor. We came to the conclusion that maybe not the plasmids (and the metabolic burden that is connected with them) are the problem, but the medium. Maybe the wrong antibiotic was added to LB. --> Prepared fresh medium for growth curves next week.
15/06/29
low copy plasmids
Sequencing result of blunt-end ligation: pICD002-6 has 3 deletions that destroy the stop codon that was supposed to be introduced, so this cannot be used. PICD002-1 also has a two-base pair deletion at the site of ligation but that does not destroy the stop codon, nor does it destroy the SpeI site of the iGEM suffix sequence. Not an ideal result but something that is good to work with! --> pICD002-1 becomes pICD002.To reduce metabolic burden for the cells, we plan to switch to low copy plasmids, namely pSB3C5 and pSB4C5. They were both available in the Spring 2015 distribution with the same insert (BBa_J04450, a lac-inducible RFP gene). --> both were transformed with DH5alpha (see: Transformation into chemocompetent cells).
15/06/29
plans
Planned growth curve experiment was aborted due to growth problems of cultures with plasmid.15/07/01
platereader
To check if the growth problems are depending on the antibiotic concentration or if the growth is different if the bacteria are taken from plate or from an overnight culture a growth curve was performed in a 24 well plate. 1,5mL of Medium (either with or without chloramphenicole (see table)) is inocculatet with a colonie from plate or with 10µL overnight culture (OD around 7,00)The results are shown in the following growthcurve:
15/07/02
sequencing
Sequencing results: PSB3C5-1 and -2: Both correct! --> pSB3C5-1 will be used from now onPSB4C5-1: Forward primer sequencing failed, reverse seqencing looks correct except for point mutation in lac promoter BBa_R0010€€
PSB4C5-2: All correct except for same point mutation as in clone 1: A to G in position 117 of BBa_R0010. Since both clones have the mutation we assume that it was already in the registry plate and will use pSB4C5-2 for further experiments.
15/07/03
clean streak
Clean streak of pSB3C5 and pSB4C5:Under the magnifier we saw colonies that were half red and half white. Due to lacI on a bacterial artificial chromosome all colonies were expected to be white.
15/07/06
cloning
We want to improve our pICD001.To accomplish this goal we decided to put 6 nucleotides between the ribosome binding site and the start of the CDI_A. For the PCR conditions and DpnI digest see protocols.PCR product purification was accomplished with QiAquickPCR Purification Kit (50)
To create a new plasmid we did a Gibson assembly with the linear PCR product:
used DNA 100 ng --> 3 µL
add 10 µL of Gibson Assembly Mastermix (2x)
add dd Water to a total volume of 20 µL
incubate 37 °C for 20 min
The product was transformed into electrocompetent cells (see protocols).
15/07/07
growth problems, cloning and platereader
Transformation was succesful. To check if the additional 6 bp were added between promoter and ribosome binding site, pICD007 was prepped with Thermo Scientific miniprep kit and eluted in 30µL.One more idea concerning our growth problems is that the chloramphenicole molecules are degraded during the first hours of an overnight culture and the plasmids are lost at the end of the overnight culture. So finally there could be a lot of living cells but only a few carry the plasmid. If this culture is used to inocculate the day culture with new chloramphenicole most of the cells die immediately.
To check this theory, we started a new platereader experiment using different concentrations of chloramphenicole. The next day we plan to plate these overnight cultures each to LB and to LB with chloramphenicole to check if the cells are dead after overnight or if they just lost the plasmid
We want to change our CDI operon from a high copy plasmid into a mid and low copy plasmid (5 and 15 copys per cell) therefore we used PCR to amplify the CDI operon, the plasmid backbone from pSB3C5 and pSB4C5 (5 and 15 copys per cell) with 3850 basepairs and 4300 basepairs. Also we amplified lacI with 1500 basepairs. In another experiment we wanted to create an polycistronic plasmid with mCherry therefore we amplifyed most of the backbone from pSB3C5 (3800bp), pSB4C5(4300bp) and again the CDI operon without RBS.
We used the following primers and templates:
| fragments | fragment 1 | fragment 2 | fragment 3 | fragment 4 | fragment 5 | fragment 6 | fragment 7 |
| template (1:100) | pSB3C5-J04450 | pSB4C5-J04450 | pICD001 | pICD001 | pSB4C5-J04450 | pSB4C5-J04450 | pICD001 |
| forward primer (10 uM) | ICD0034 | ICD0034 | ICD001 | lacI, AaII rev | ICD0036 | ICD0036 | ICD0038 |
| reverse primer (10 uM) | ICD0035 | ICD0035 | ICD008 | ICD0033 | ICD0037 | ICD0037 | ICD0039 |
| desired fragment length | 3850 bp | 4300 bp | 11500 bp | 1500 bp | 3800 bp | 4300 bp | 11500 bp |
15/07/08
gibson assembly, plating of platereader wells
The cultures of wells A2, A3, A4, D2, D3, D4 are diluted 1:100 twice. 20µL are plated each on LB and LB+CAM Agar platesFor the gibson assembly to creat our new plasmids we need to purificate our PCR products. Purification was accomplished with QiAquickPCR Purification Kit (50)
Transformation
Plating of cultures from plate reader:
The cultures of wells A2, A3, A4, D2, D3, D4 are diluted 1:100 twice (--> 1:10000).
20µL are plated each on LB and LB+CAM Agar plates. This way we are trying to find out how many cells are actually alive in our overnight culture and how many of those still have our plasmid. Only if we have roughly the same number of colonies on the LB+CAM plate as on the LB-only plate, we can be sure that all cells still harbor the plasmid.
G.A. reaction:
| fragments | volume |
| Fragment 1 | 0.76 uL (=36.7 ng = 0.14 pmol) |
| Fragment 3 | 1.88 uL (=100 ng = 0.14 pmol) |
| Fragment 4 | 0.32 uL (=13.8 ng = 0.14 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 7.04 uL |
| fragments | volume |
| Fragment 2 | 0.68 uL ( 40.9 ng = 0.14 pmol) |
| Fragment 3 | 1.88 uL (=100 ng = 0.14 pmol) |
| Fragment 4 | 0.32 uL (=13.8 ng = 0.14 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 7.12 uL |
| fragments | volume |
| Fragment 5 | 0.60 uL (=36.7 ng = 0.14 pmol) |
| Fragment 7 | 2.22 uL (=100 ng = 0.14 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 6.84 uL |
| fragments | volume |
| Fragment 6 | 0.99 uL (=40.9 ng = 0.14 pmol) |
| Fragment 7 | 2.22 uL (=100 ng = 0.14 pmol) |
| G.A. master mix | 10 uL |
| ddH2O | 6.84 uL |
15/07/09
results from platereader
Counting of the colonies from the overnight plate reader experiment:Numbers are: Colonies per CAM plate / colonies per LB plate
(The CAM-plates had the SAME antibiotics concentration (34 ug/ml) ONLY the media in the plate reader experiment had varying concentrations.)
Outcome:
• CDI002 (harbors high copy plasmid, ca. 200 copies per cell) needs high CAM concentration to keep up the selection pressure. Otherwise cells lose the plasmid.
• DH5alpha with pSB3C5 (10 - 12 copies per cell) counterintuitively seems to lose the plasmid at high chloramphenicol concentrations, whereas the cells seem to keep it at low concentrations
• Same applies to DH5alpha harboring pSB4C5 (ca. 5 copies per cell). This however grows much worse.
15/07/14
SDS-Page
Preparing of SDS-Page samples for pCDI007: We wanted to see the expression of the CDI operon with the new spacer sequence between RBS and startcodon. Result of the SDS page (data not shown): no signals form any Cdi operon protein can be found. Maybe we need to change the strain or use a lowcopy plasmid in oder to decrease the metabolic burden.Samples of the overnight culture were plated out on LB Agar and LB Agar + Chloramphenicol plates. To see if our E.coli cells lose our Plasmid. On both plates we counted equal colonies.
Test Digest of pCDI003_1, pCDI003_2, pCDI003_3, pCDI004_1, pCDI004_2, pCDI004_3, pCDI005_1, pCDI005_2, pCDI005_3, pCDI006_1, pCDI006_2,pCDI006_3.
Result of this test digest (picture not shown) all plasmids show signals in not exspected areas. To gain the new constructs we will do the Gibson assemblys again.
Gibson assembly: Protocoll 15-07-08.
15/07/15
SDS-Page
The transformants (pICD003=reaction 1, pICD004=reaction 2, pICD005=reaction 3, pICD006=reaction4) of the Gibson assembly are streaked out on Agar-Plates and from the same colonies some cells are used to inocculate overnight cultures for Miniprep.We wanted to see if our SDS-Pages from pCDI007, pCDI002 and the wildtyp differ from each other. We obtain no difference between the aliquots of the different constructs . So far we only can see expression of the chloramphenicol resistance protein.
15/07/16
Plasmidisolation
Miniprep of pICD003, pICD004, pICD005 and pICD006 according to Thermo Scientific protocol. Elution in 30µL elution bufferTest digest: To see with which plasmid we want to work form here on we used a test digest to get further information about our gained plasmids.
We used the restriction enzyms EcoRI and fragments with 6 kBp and 8 kBps were expected.
So far fragments were obtained as exspected in a next step we will sequence our new constructs.
So far fragments were obtained as exspected in a next step we will sequence our new constructs. Overnight cultres for pCDI007 in W3110-RFP and W3110-RFP were inoculated.
15/07/17
Plasmidisolation
We wanted to prepare another SDS Page with pCDI007 in W3110-RFP and to compare this result we also prepared W3110-RFP as a control.The experiment could not be finished because grow problems ocured.
Another Test Digest of the samples from pCDI005 and pCDI006 with pICD001 as a control was prepared. So far fragments were obtained as exspected in a next step we will sequence our new constructs. 15/07/20
sequencing
The sequenced constructs were not as exspected. The experimental design have to change to get better cloning results. 15/07/21PCR, overnight culutres
PCR of 15-07-07 was repeated because the Gibson Assembly did not work.Overnight cultures of CDI003, CDI007, W3110 and W3110-RFP are grown to start a killing assay and an SDS PAGE the next day 15/07/22
PCR, overnight culutres
