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Notebooks

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Notebooks

Introduction

On this page, all experiments performed in our wet lab are recorded by date. Detailed experiment protocols are provided in theexperiment page and are therefore not described in this page



7.27

V.natriegens activation

XIRAN HU

Freeze-dried V.natriegens ATCC14048 ordered from CCIC was activated in LB+v2 salts overnight.

7.28

XIRAN HU

Glycerol stock

JINXUAN LU, JINPENG LI

Overnight culture of V.natriegens was stored as glycerol stock for later use.

Growth curve measurement

Three different mediums were inoculated with overnight V.natriegens culture to measure the growth curve. The result was as follows:

8.3

Stab culture activation

XIRAN HU

Top 10 strains carrying plasmids ordered from Azenta are activated from stab culture into liquid culture(LB broth with appropriate antibiotics).

8.4

ZIWEN XU

Plasmid extraction

XIRAN HU

Plasmids pGFP, pdCas9-sg1 and pPilin were extracted from Top 10 liquid culture. Concentration and quality of the plasmids were measured with Nanodrop.

pGFP

pdCas9-sg1

pPilin

concentration(ng/μL) 352.9 38.5 371.8
OD260/280 1.89 1.77 1.90
OD260/230 2.18 2.31 1.15

pdCas9-sg1 can not be used for transformation.

Glycerol stock

XIRAN HU

3 Top 10 strains were stored as glycerol stock for later use.

Chemical competent cell preparation

YUCHENG ZHANG

Prepare chemical competent V.natriegens for transformation.The chemical competent cells were stored at -80℃ until use.

8.5

Transformation of chemical competent cells

ZIWEN XU

The transformation was performed on home-made chemical competent V.natriegens and comercial DH5α with the following parameters

number

Cell type

plasmid name

Plasmid concentration(μg/μL)

Plasmid quantity(μL)

1 DH5α pPilin 371.8 1
2 DH5α pPilin 37.18 2
3 V.natriegens pPilin 371.8 1
4 V.natriegens pPilin 37.18 2
5 DH5α pGFP 352.9 1
6 DH5α pGFP 35.29 2
7 V.natriegens pGFP 352.9 1
8 V.natriegens pGFP 35.29 2

8.6

XIRAN HU

Colony PCR

The result of the overnight Agar plate cultures was as follows.There were several colonies on the plates corresponding to DH5α transformations but only one colony on transformation 7.

Several colonies were selected to conduct colony PCR with appropriate primers.The result is as follows:

All positive strains were stored as glycerol stock. DH5α cells transformed with pPilin were designated as EP1, EP2, EP3 and DH5α cells transformed with pGFP were designated as EG1, EG2, EG3

EP2 overnight culture

XIRAN HU

Strain EP2 was inoculated in 2mL of LB broth culture with 100μg/mL of Ampicilin for pilin induction.

Transformation of chemical competent cells

XIRAN HU

The transformation was performed on home-made chemical competent V.natriegens with the following parameters

number

Cell type

plasmid name

Plasmid concentration(μg/μL)

Plasmid quantity(μL)

1 V.natriegens pGFP 352.9 1
2 V.natriegens pGFP 35.29 2

8.7

Colony PCR

YUCHENG ZHANG

There were 2 colonies on the plate corresponding to transformation 1. Colony PCR was conducted on these 2 colonies with appropriate primers. But no band was seen.

EP2 extended culture and pilin induction

YUCHENG ZHANG

2×30 mL of LB broth with 100μg/mL of Ampicilin were inoculated with overnight EP2 liquid culture. Arabinose solution, the inducer, was added to one tube when OD600 of the liquid culture in it reached 0.5. And then the culture continued for 5h before harvest.

Protein extraction from EP2

ZIWEN XU

Soluable proteins were extracted and collected from EP2 after the induction.

Pilus harvest

XIRAN HU

Pilus were harvested according to the protocol from EP2 culture.

BCA test of soluable proteins extracted from EP2

XIRAN HU

BCA test of soluable proteins extracted from EP2

8.9

ZIWEN XU

Whole cell lysates WB for Pilin identification

Overnight culture of EP2 was inoculated to the following culture mediums, 1.5mL for each condition:

Culturing time\induction concentration

0

10mM

20mM

10h 1 2 3
24h 4 5 6

The induction of pilin expression was performed when the OD600 reached 0.5 by arabinose solution.

After stained with coomassie brilliant blue, no significant difference was seen between groups. The following steps were performed according to the protocols. No band was seen.

8.12

XIRAN HU

Glycerol stocks of the top 10 strains carrying plasmids ordered from Azenta were inoculated into liquid culture (LB broth with appropriate antibiotics). A glycerol stock of wild type Vibrio natriegens was inoculated into LB+v2 salt liquid medium for tomorrow's electrocompetent cells preparation.

8.13

Plasmid extraction

ZIWEN XU

Plasmids pGFP, pdCas9-sg1 and pPilin were extracted from Top 10 liquid culture. Concentrations and qualities of the plasmids were measured with Nanodrop.

pGFP

pdCas9-sg1

pPilin

concentration(ng/μL) 220.5 159.7 180.3
OD260/280 1.82 1.88 1.88
OD260/230 1.95 2.01 2.14

Ectrocompetent cells preparation(protocol 1)

YUCHENG ZHANG

Electrocompetent Vibrio natriegens were prepared as described in the protocol.

Electroporation

XIRAN HU

Electroporation was performed according to the protocol with the following parameters:

number

voltage(v)

time(ms)

1 700 1
2 700 2
3 700 3
4 700 4

8.14

YUCHENG ZHANG

Electroporation result

There was no colony on the plates.

Electrocompetent cells preparation(protocol 1)

Electrocompetent Vibrio natriegens were prepared as described in the protocol.

8.15

XIRAN HU

Electroporation

Electroporation was performed according to the protocol with the following parameters:

number

voltage(v)

time(ms)

1 700 1
2 700 2
3 800 1
4 800 1.7
5 820 1.8
6 900 1

Whole cell lysates WB for pilin identification

XIRAN HU

Overnight culture of EP2 was inoculated into the following mediums:

Number

Inducer concentration

Culturing time after induction

1 0mM 5h
2 10mM 5h
3 20mM 5h
4 0mM 15h
5 10mM 15h
6 20mM 15h

After transfer, the PVDF membrane was stained with Ponceau S. No band was seen, perhaps due to the unstable current of the electrophoresis system.

8.17

XIRAN HU

Electroporation result

There was no colony on the plates.

electroporation

Electroporation was performed according to the protocol with the following parameters:

number

voltage(v)

time(ms)

1 700 2.2
2 790 2.2
3 900 2.2
4 800 2.3
5 740 2.2
6 840 2.2

Transformation of chemical competent BL21(DE3) cells

ZIWEN XU

Comercial chemical competent BL21(DE3) cells were transformed with 3μL(684 ng) of pPilin according to the protocol.

8.18

Colony PCR

YUCHENG ZHANG

There were several colonies on the plate of BL21 transformation. Colony PCR was conducted on 4 of these colonies with appropriate primers. The result was as follows.

Strain corresponding to band 1 was designated as BP1.

BP2 extended culture and pilin induction

XIRAN HU

2×30 mL of LB broth with 100μg/mL of Ampicilin were inoculated with overnight EP2 liquid culture. Arabinose solution, the inducer, was added to one tube when OD600 of the liquid culture in it reached 0.5. And then the culture continued for 5h and 15h before harvest.

8.19

XIRAN HU

Whole cell lysates SDS-PAGE for pilin identification

Samples for SDS-PAGE were prepared from the following mediums:

number

Inducer concentration

Culturing time after induction

1 0mM 5h
2 20mM 5h
3 0mM 15h
4 20mM 15h

No significant difference in the molecular weight of pilin was seen between the lanes.

Electrocompetent cell preparation (protocol 2)

YUCHENG ZHANG

Electrocompetent cells were prepared according to the protocol.

Electroporation

XIRAN HU

Electroporation was performed according to the protocol with the following parameters:

Plasmid

Plasmid volume(μL)

voltage(v)

time(ms)

pPililn 5 700 2.2
pPilin 5 790 2.2
pGFP 5 900 2.2
pGFP 5 800 2.3
pdCas9-sg1 5 740 2.2
pdCas9-sg1 5 840 2.2

8.20

YUCHENG ZHANG

Colony PCR

There were several colonies on the plates. Colony PCR was conducted on 11 of these colonies with appropriate primers. The result was as follows.

Strains tested positive were designated as V.CR1, V.CR2, V.CR3, V.CR4, V.CR5, V.PL V.GF3 and V.GF4.

8.21

V. CR1 extended culture and dCas9 induction

ZIWEN XU

Overnight V. CR1 culture was inoculated into the following mediums.Inducer was added when the OD600 reached 0.5.

number

Inducer concentration(mg/mL)

Culturing time after induction

1 0 5h
2 0.5 5h
3 1 5h
4 0 15h
5 0.5 15h
6 1 15h

8.22

ZIWEN XU

Whole cell lysates SDS-PAGE for dCas9 identification

1 mL of each V.CR1 culture was centrfuged and the pellets were resuspended with 35 μL of ddH2O.

10 μL of 5×loading buffer was added to each of the tubes and the tubes were incubated at 95℃ for 5 min. 10 μL of prepared samples were loaded.

There was no significant difference in the molecular weight of dCas9 between lanes.

8.24

Green fluorescence observation

YUCHENG ZHANG

Overnight V.GF4 culture and Vibrio natriegens 14048 culture were enlarged for 2 hours.

The fluorescence was observed with fluorescence microscope. There was no significant difference between strain 14048 and V.GF4.

Pilin induction in V.PL

XIRAN HU

Overnight V.PL culture was inoculated into the following mediums at a dilution ratio of 1:100. Induction was performed 2h after the inoculation.

number

inducer(arabinose) concentration

Culturing time after induction

Medium volume

temperature

1 0mM 11h 30mL 37℃
2 0mM 11h 30m 37℃
3 20mM 11h 30mL 37℃
4 20mM 11h 30mL 37℃

8.25

XIRAN HU

Pilus harvest

Culture number 1 and 2 were consolidated while number 3 and 4 were consolidated. Pilus were harvested according to the protocol. The BCA test result of the two acquired samples was as follows.

Sample1 was from uninduced culture while sample2 was from induced culture. The final concentrations of the two samples were 0.39μg/μL and 0.28μg/μL, respectively.

1.5mL of sample1 and sample 2 were centrifuged to prepare whole cell lysate samples designated as sample1-1 and sample2-1

Pilin WB

XIRAN HU

WB of pilin was performed on sample1, sample1-1, sample2 and sample2-1 according to the protocol.

8.26

WB result

XIRAN HU

There was no band on the membrane. The secondary antibody was not adequately washed off and small protein bands were too obscure to be observed. Tris-tricine SDS-PAGE should be used for pilin WB.

Extended culture of V.CR1 and dCas9 induction

ZIWEN XU

Overnight V.CR1 culture was inoculated into the following mediums. Inducer was added when the OD600 reached 0.5.

number

Inducer concentration(mg/mL)

Culturing time after induction

1 0 6h
2 0.5 6h

Whole cell lysates SDS-PAGE for dCas9 identification

ZIWEN XU

1mL of each culture above was centrifuged and the pellets were resusppended with 35μL of ddH2O. 5uL of each of the prepared samples were loaded for SDS-PAGE. The result is as follows. The band marked with * was darker on the induced lane and the molecular weight of dCas9(about 150kDa) is between 180kDa and 130kDa.

8.27

Whole cell lysates SDS-PAGE for sfGFP identification

YUCHENG ZHANG

1 mL of overnight V.GF4 culture and 14048 culture were centrifuged and the pellets were resuppended with ddH2O. 5 μL of 5×loading buffer was added to the tubes which were then incubated at 95℃ for 5mins. 5 μL of each of the prepared samples was loaded for SDS-PAGE.

There were too many bands to distinguish the differences.

Electrocompetent cell preparation (protocol 2)

YUCHENG ZHANG

Overnight V.PL and V.CR1 culture were used for electrocompetent cell preparation according to the protocol.

Electroporation

XIRAN HU

Electroporation was performed according to the following parameters.

number

Competent cell

plasmid

Plasmid volume(μL)

time(ms)

voltage(v)

antibiotics

1 V.CR1 pPilin 5 4 790 Ampicilin
2 V.CR1 pPilin 5 4 790 Ampicilin
3 V.PL pdCas9-sg1 5 3.8 790 Kanamycin
4 V.PL pdCas9-sg1 5 4 790 Kanamycin

8.28

V. CR1 extended culture and dCas9 induction

ZIWEN XU

Overnight V. CR1 and ATCC14048 culture was inoculated into the following mediums. Inducer was added when the OD600 reached 0.5.

number

cell

Inducer concentration(mg/mL)

Culturing time after induction

1 WT 0 5h
2 V.CR1 0 5h
3 V.CR1 0.5 5h
4 V.CR1 0.5 10h

SDS-PAGE of dCas9

ZIWEN XU

Soluable proteins were extracted from 1.5 mL of the cultures above. The result of SDS-PAGE was as follows:

There was no significant difference between the 4 lanes.

SDS-PAGE of sfGFP

YUCHENG ZHANG

1 mL of overnight V.GF4 and ATCC14048 culture were centrifuged and then resuspended with 35 μL of ddH2O. 1.5 mL of overnight V.GF4 and ATCC14048 culture were used for soluable protein extraction. The result of SDS-PAGE was as follows.

There was a significant darker band on the lane of V.GF4 soluable proteins(marked with).The molecular weight of the modified sfGFP is about 31kD, between 25kD and 35kD. The experiment would be repeated 2 times to ensure the result.

9.8

pGFP modification

YUCHENG ZHANG

Reversed PCR

Component

Volume

2 × Phanta Flash Master Mix 25μL
ddH2O 20μL
CutF+R(5μM) 4μL
pGFP 1μL
annealing temperature 59℃
elongation time 20sec

Gel extraction

The linearized pGFPcut was purified from PCR mix.

Gibson assembly

Component

Volume

Linearized pGFP 1 μL(333ng)
2×CE mix 5μL
ddH2O 4μL

The recombinant product (desingated as pGFPcut) was transformed into electrocompetent V.natriegens cells.

SDS-PAGE of sfGFP

XIRAN HU

1 mL of overnight V.GF4 and ATCC14048 culture were centrifuged and then resuspended with 35 μL ddH2O. 1.5mL overnight V.GF4 and ATCC14048 culture were used for soluable protein extraction. The result of SDS-PAGE was as follows.

There was a significantly darker band in the lane of V.GF4 soluable proteins (marked with'*').The molecular weight of the modified sfGFP is about 31kD, between 25kD and 35kD. The experiment will be repeated one more time to confirm the result.

Electroporation

XIRAN HU

Electroporation was performed according to the following parameters.

number

Competent cell

plasmid

Plasmid volume(μL)

time(ms)

voltage(v)

antibiotics

1 V.CR1 pPilin 5 3.7 790 Amp(40μg/mL)
2 V.PL pdCas9-sg1 5 4 790 Kan(50μg/mL)

Pilin induction in V.PL

XIRAN HU

Overnight V.PL culture was inoculated into the following mediums at a dilution ratio of 1:100. Induction was performed 2h after the inoculation.

number

Cell type

inducer(arabinose) concentration

Culturing time after induction

Medium volume

temperature

1 WT 20mM 16h 30mL 37℃
2 V.PL 20mM 16h 30m 37℃

9.9

YUCHENG ZHANG

Colony PCR

There were several colonies on the plate supplemented with Kanamycin. 2 colonies were chosen to conduct colony PCR with the following parameters:

pPilin verification

Component

Volume

2 × Taq Master Mix 25μL
ddH2O 20μL
PLR+PLF(5μM) 4μL
colony 1

pdCas9-sg1 verification

Component

Volume

2 × Taq Master Mix 25μL
ddH2O 20μL
CRR+CRF(5μM) 4μL
colony 1

Bands were only seen on the lanes corresponding to pdCas9-sg1 verification. The electroporation was not successful.

SDS-PAGE of Pilin

XIRAN HU

1.5 mL of each of the 4 cultures were used for soluable protein extraction. 10μL of prepared sample was loaded. The result of SDS-PAGE was as follows. The issue may lie in the gel or loading buffer.

9.10

SDS-PAGE of sfGFP

YUCHENG ZHANG

1 mL of overnight V.GF4 and ATCC14048 culture were centrifugedand then resuspended with 35 μL ddH2O. 1.5mL of overnight V.GF4 and ATCC14048 culture were used for soluable protein extraction. The result of SDS-PAGE was as follows. a stands for all proteins and s stands for extracted soluable proteins.

There was a significant darker band on the lane of V.GF4 soluable proteins (marked with'*' ).The molecular weight of the modified sfGFP is about 31kD, between 25kD and 35kD.

Gibson assembly

ZIWEN XU

The linearized pGFP solution was diluted to 67.26 μg/mL.

Component

Volume

Linearized pGFP(diluted) 4 μL
2×CE mix 5 μL
ddH2O 1 μL

Chemical and electrocompetent cell prepareation (protocol 2)

YUCHENG ZHANG

Electroporation competent V.PL and V.CR1 were prepared according to the protocols.

Electroporation

Electroporation was performed according to the protocol with the following parameters.

Cell type

plasmid

Plasmid volume(μL)

voltage(v)

time(ms)

V.CR1 pPilin 5 790 4
V.CR1 pGFPcut 5 790 3.9
V.PL pdCas9-sg1 5 790 4

Transformation of chemical competent DH5α

ZIWEN XU

2 μL of modified pET-24b(+) was added to 50 μL of chemical competent DH5α for transformation.

Pilin induction in V.PL

XIRAN HU

Overnight V.PL culture was inoculated into the following mediums at a dilution ratio of 1:100. Induction was performed 2h after the inoculation.

number

Cell type

inducer(arabinose) concentration

Culturing time after induction

Medium volume

temperature

1 WT 20mM 20h 2×30mL 16℃
2 V.PL 20mM 20h 2×30mL 16℃

9.11

XIRAN HU

Modified pET-24(+) carrying strain storage.

There was no colony on the plates of electroporation, maybe due to the overly used electroporation cuvettes. There were many colonies on the plate of DH5α transformation and 5 colonies were chosen to be strored.

Pilus harvest and SDS-PAGE of pilin

XIRAN HU

Pilus were harvested according to the protocol. The BCA test result of the harvested pilus solution was as follows.

According to the result, the concentration of sample1 (induced V.PL) was 0.46μg/μL and the concentration of sample2(WT) was 1.04μg/μL.

Electroporation

YICHEN LIU

Electroporation was performed according to the protocol with the following parameters.

Cell type

plasmid

Plasmid volume(μL)

voltage(v)

time(ms)

V.CR1 pPilin 5 790 4
V.PL pdCas9-sg1 5 790 4

9.12

Colony PCR

XIRAN HU

5 colonies on the plates were chosen for colony PCR with the following parameters

pPilin verification

Component

Volume

2 × Taq Master Mix 25μL
ddH2O 20μL
PLR+PLF(5μM) 4μL
colony 1

pdCas9-sg1 verification

Component

Volume

2 × Taq Master Mix 25μL
ddH2O 20μL
CRR+CRF(5μM) 4μL
colony 1

The result was as follows. Strains that had bands in both PCR tests were stored as glycerol stock and designated as V.PC1, V.PC3, V.PC5, V.PC6 and V.PC7, respectively.

WB of harvested pilin

XIRAN HU

Step

Details

blocking 5% silk milk dissolved in TBST, 1.5h at RT
Primary antibody 1:4000, overnight at 4℃
Secondary antibody 1:5000, 1h at RT

9.13

WB of harvested pilin

The result of the WB was as follows. Marker bands of low molecular weight could not be seen, maybe because the transfer buffer was not supplemented with 20% of methanol.

Plasmid exraction

XIRAN HU

Plasmids were extracted from overnight culture of V.PC1, V.PC3, V.PC5, V.PC6, V.PC7 for sequencing.

Electroporation

YICHEN LIU

number

Cell type

plasmid

Plasmid volume

voltage

time

1 V.CR1 pGFPcut 5 μL 790v 4ms
2 ATCC14048 Control plasmid 5 μL 790v 4ms

V.CR1 extended culture and dCas9 induction

ZIWEN XU

Overnight V.CR1 culture was inoculated into the following mediums. Inducer was added when the OD600 reached 0.5.

number

Cell type

Inducer concentration(mg/mL)

Culturing time after induction

temperature

1 WT 0 20h 20 ℃
2 V.CR1 0.5 20h 20℃

9.15

pGFP modification

YUCHENG ZHANG

Reversed PCR

Component

Volume/Details

2 × Phanta Flash Master Mix 25μL
ddH2O 20 μL
modF1+R1(5μM) 4 μL
pGFP 1 μL
annealing temperature 53℃
elongation time 21sec

Gel extraction:Linearized pGFPmod1 was purified from PCR mix.

Gibson assembly

Component

Volume/Details

Linearized pGFP 2 μL(256ng)
2×CE mix 5 μL
ddH2O 3 μL

The recombinant product (desingated as pGFPmod1) was transformed into chemical competent DH5α cells according to the protocol.

Pilin induction in V.PC6

XIRAN HU

Overnight V.PC6 culture was inoculated into the following mediums at a dilution ratio of 1:100. Induction was performed 2h after inoculation.

Parameter

Details

Cell type V.PC6
inducer(arabinose) concentration 20mM
Culturing time after induction 24h
Medium volume 2×200 mL
temperature 20℃

SDS-PAGE of dCas9

ZIWEN XU

1 mL of induced V.CR1 and ATCC14048 culture were centrifuged and then resuspended with 35 μL of ddH2O. 1.5mL of overnight V.GF4 and ATCC14048 culture were used for soluable protein extraction. The result of SDS-PAGE was as follows. There was no significant difference between the two lanes.

9.16

Pilus harvest

XIRAN HU

Pilus were harvested according to the protocol. The BCA test result of the harvested pilus solutions was as follows. Concentration was 4.92μg/μL of sample1 , 4.62μg/μL of sample2, and 0.88μg/μL of sample3.

Chemical competent DH5α preparation

YUCHENG ZHANG

Chemical competent DH5α was prepared according to the protocols.

DH5α transformation

ZIWEN XU

Recombinant pGFPmod1 was transferomed into chemical competent DH5α cells accroding to the protocol.

9.17

XIRAN HU

WB of pilus

10 μL 2×tricine loading buffer was added to 40 μL of sample1 and sample2 respectively. Then the tubes were incubated at 95℃ for 5mins. 20.3μL of prepared sample1 and 21.8μL of prepared sample2 were loaded for SDS-PAGE. The primary antibody was diluted at 1:500.

Colony PCR

YUCHENG ZHANG

7 colonies on the plates were chosen for colony PCR with the following parameters

pPilin verification

Component

Volume/Details

2 × Taq Master Mix 25μL
ddH2O 20μL
GFR+GFF(5μM) 4μL
colony 1

The result was as follows.All colonies tested positive. Strains corresponding to band 1 and band 2 were chosen to conduct the following experiments and were designated as V.mod1-1 and V.mod1-2.

Pilin induction in V.PC6

XIRAN HU

Overnight V.PL culture was inoculated into the following mediums at a dilution ratio of 1:100. Induction was performed 2h after inoculation.

Cell type

V.PC6

ATCC14048

inducer(arabinose) concentration 20mM 20mM
Culturing time after induction 24h 24h
Medium volume 100 mL 100mL
temperature 20℃ 20℃

9.18

WB of pilus

XIRAN HU

The secondary antibody was diluted at 1:5000. No band was seen on the membrane.

Gibson assembly and DH5α transformation

YICHENG ZHANG, ZIWEN XU

gibson assembly

Component

Volume/Details

Linearized pGFP 2 μL(256ng)
2×CE mix 5 μL
ddH2O 3 μL

The recombinant product (desingated as pGFPcut) was transformed into chemical competent DH5α cells according to the protocol.

9.19

Plasmid extraction

ZIWEN XU

Plasmids were extracted from overnight culture of V.mod1-1 and V.mod1-2.

Pilus harvest and SDS-PAGE of pilin

Pilus were harvested according to the protocol. The BCA test result was as follows. Sample 1 was harvested from V.PC6 culture and sample 2 was harvested from ATCC14048 culture.

Colony PCR

YUCHENG ZHANG

One colony on the plates was chosen for colony PCR with the following parameters.

pPilin verification

Component

Volume/Details

2 × Taq Master Mix 25μL
ddH2O 20μL
GFR+GFF(5μM) 4μL
colony 1

The result was as follows.The colony tested positive and was designated as V.cut.

pGFP modification

YUCHENG ZHANG

Reversed PCR

PCR Parameters

Component

Volume/Details

2 × Phanta Flash Master Mix 25μL
ddH2O 20 μL
modF2+R2(5μM) 4 μL
pGFPmod1 1 μL
annealing temperature 56℃
elongation time 21sec
Gel extraction

Linearized pGFPmod2 was purified from PCR mix.

Gibson assembly

Component

Volume/Details

Linearized pGFPmod1 2 μL(256ng)
2×CE mix 5 μL
ddH2O 3 μL

The recombinant product (desingated as pGFPmod2) was transformed into chemical competent DH5α cells according to the protocol.

DH5α transformation

ZIWEN XU

Recombinant pGFPmod2 was transferomed into chemical competent DH5α cells accroding to the protocol.

9.20

YUCHENG ZHANG

Chemical competent DH5α preparation

YUCHENG ZHANG

Chemical competent DH5α was prepared according to the protocols.

Plamisd extraction

XIRAN HU

Plamis was extracted from overnight culture of V.cut

DH5α transformation

XIRAN HU

Recombinant pGFPmod2 was transferomed into chemical competent DH5α cells accroding to the protocol.

9.21

Colony PCR

YUCHENG ZHANG

Five colonies on the plates was chosen for colony PCR with the following parameters.

pPilin verification

Component

Volume/Details

2 × Taq Master Mix 25μL
ddH2O 20μL
GFR+GFF(5μM) 4μL
colony 1

The result was as follows.One of the colonies tested positive was chosen for the following experiments.

Spread plate

XIRAN HU

Overnight V.PC1 culture was spread out on twenty agar plates supplement with kanacymin, ampicillin, 0.5% glycerol and 2% arabinose. 300μL of culture was spread for each plate.The plates were cultured at 37℃ for 24 h before pilus harvest.

Electroporation

XIRAN HU

Cell type

ATCC14048

plasmid pGFPcut
Plasmid volume 5 μL
voltage 790 v
time 4 ms

9.22

Electroporation

YUCHENG ZHANG

no.

Cell type

plasmid

Plasmid volume

voltage

time

1 V.CR1 pGFPcut 5 μL 790 v 4 ms
2 V.CR1 pGFPmod2 5 μL 790 v 4 ms

Pilus harvest

XIRAN HU

The cells were harvested from the plates with 1 mL of LB+v2 salts medium for each plate.The following procedures were the same as the previous harvest protocol.

The concentration of harvested pilus solution was tested using the previous standard curve.The concentration of original pilus solution was about 4.8μg/μL

9.23

Electroporation

YICHEN LIU

no.

Cell type

plasmid

Plasmid volume

voltage

time

1 V.CR1 pGFPcut 5 μL 790 v 4 ms
2 V.CR1 pGFPmod2 5 μL 790 v 4 ms

electrocompetent cell prepareation (protocol 2)

YUCHENG ZHANG

Electroporation competent V.CR1 were prepared according to the protocols.

9.24

Colony PCR

Six colonies from the plate of electroporation no.1 and five from no.2 were chosen for colony PCR.

pPilin verification

Component

Volume/Details

2 × Taq Master Mix 25μL
ddH2O 20μL
GFR+GFF(5μM) 4μL
colony 1

The result is as follows. Two strains(designated as V.CR-cut and V.CR-mod respectively) were chosen to perform the following experiments.

Spread plate

ZIWEN XU

Overnight V.PC1 culture was spread out on twenty agar plates supplement with kanacymin, ampicillin, 0.5% glycerol and 2% arabinose. 300μL of culture was spread for each plate.The plates were cultured at 37℃ for 24 h before pilus harvest.

electrocompetent cell prepareation (protocol 2)

YUCHENG ZHANG

Electroporation competent ATCC14048 were prepared according to the protocols.

9.25

Electroporation

XIRAN HU

no.

Cell type

plasmid

Plasmid volume

voltage

time

1 ATCC14048 pGFPcut 5 μL 790 v 3 ms
2 ATCC14048 pGFPmod2 5 μL 790 v 3 ms

Green fluorescence measurement

XIRAN HU

Overnight culture of V.CR-cut and V.CR were used for green fluorescence measurement with microplate reader.The excitation light was 488 nm and emitted light was 535 nm. The result was as follows.

9.26

Pilus harvest

XIRAN HU

The cells were harvested from the plates with 1 mL of LB+v2 salts medium for each plate.The following procedures were the same as the previous harvest protocol.The BCA test result was as follows.The concentration of harvested pilin solution was 4.42 μg/μL.

Sample preparation for TEM

XIRAN HU

The pilin solution was seriously diluted. 5 μL of each sample was dropped on 200-mesh carbon-coated copper

grids and let air-dried for 2 h.Then the samples were stained by uranium acetate and dried at 4 ℃ overnight.

Colony PCR

XIRAN HU

Five colonies from the plate of electroporation no.1 and two from no.2 were chosen for colony PCR.

The result is as follows. Two strains(designated as V.cut and V.mod respectively) were chosen to perform the following experiments.

9.27

YICHEN LIU, YUCHENG ZHANG

Transmission electron microscopy

The result of TEM was as follows.There was too much impurity in our sample, so we could not acquire the structure of our pilus film.

9.28

Spread plate

ZIWEN XU

Overnight V.PC1 culture was spread out on twenty agar plates supplement with kanacymin, ampicillin, 0.5% glycerol and 2% arabinose. 300μL of culture was spread for each plate.The plates were cultured at 30℃ for 24 h before pilus harvest.

9.29

Spread plate

ZIWEN XU

Overnight culture of V.cut and V.mod was spread out on agar plates supplement with Ampicillin and cultured for 24 h before harvest to test the fluorscence intensity.

9.30

Pilus harvest and purification

XIRAN HU, ZIWEN XU

The cells were harvested from the plates with 1 mL of LB+v2 salts medium for each plate.The following procedures were the same as the previous harvest protocol(protocol 2). The harvested pilus solution was purified by Ni-NTA resin.

SDS-PAGE of pilin

ZIWEN XU

15 μL of washing 4 and elution 1 and elution 2 were loaded for SDS-PAGE. No obvious bands could be seen , maybe because the duratio of second ammonium sulfate precipiation was too short.

pdCas9-sg modification

YUCHENG ZHANG

Component

Volume/Concentration

2 × Phanta Flash Master Mix 25uL
ddH2O 20uL
repF+R(5 μM) 4uL
pdCas9-sg 1uL
annealing temperature 59℃
elongation time 40 sec

Gel extraction

Linearized pGFPmod1 was purified from PCR mix.

Gibson assembly

Component

Volume/Concentration

Linearized pdCas9-sg 2 μL(256ng)
2×CE mix 5uL
ddH2O 3uL

The recombinant products (desingated as pdCas9-sg2, pdCas9-sg3 and pdCas9-sg4) were transformed into chemical competent DH5α cells according to the protocol.

10.1

Colony PCR

XIRAN HU

Colonies from the plates of DH5α transfromed with modified pdCas9-ga were chosen for colony PCR. The result was as follows.One colony from each plate(designated as E.sg2, E.sg3 and E.sg4 respectively.) were chosen for the following experiments.

pPilin verification

Volume/Concentration

2 × Taq Master Mix 25uL
ddH2O 20uL
CRR+CRF(5uM) 4uL
colony 1

Spread plates

ZIWEN XU

Overnight V.PC1 culture was spread out on twenty agar plates supplement with kanacymin, ampicillin, 0.5% glycerol and 2% arabinose. 300uL of culture was spread for each plate.The plates were cultured at 30℃ for 48 h before pilus harvest.

10.3

Pilus harvest and purification

XIRAN HU

The cells were harvested from the plates with 1 mL of LB+v2 salts medium for each plate.The following procedures were the same as the previous harvest protocol(protocol 2). The harvested pilus solution was purified by Ni-NTA resin.

10.6

SDS-PAGE of pili

XIRAN HU

10 μL of all washing and elution solution were loaded for SDS-PAGE. The result was as follows.

10.9

Electroporation

XIRAN HU

number 1 2 3
Cell type ATCC14048 ATCC14048 ATCC14048
plasmid pdCas9-sg3 pdCas9-sg4 pdCas9-sg1
Plasmid volume 5 μL 5 μL 5 μL
voltage 800 V 800 V 800 V
time 4 ms 4 ms 4 ms

Chemical competent DH5α preparation

YUCHENG ZHANG

Chemical competent DH5α was prepared according to the protocols.

Conductance measurement

Electric resistance of pili solution and supplemented with different antibodies were measured with a multimeter.While maintaining a relatively constant filament concentration, we introduced equal concentrations of different antibodies (with antibody solution volume much smaller than the filament solution volume) into the solution.The result was as follows.

10.10

Electrocompetent cell prepareation (protocol 2)

YUCHENG ZHANG

Electroporation competent ATCC14048 were prepared according to the protocols.

Electroporation

XIRAN HU

number 1 2 3 4
Cell type V.mod V.mod V.mod V.mod
plasmid pdCas9-sg1 pdCas9-sg2 pdCas9-sg3 pdCas9-sg3
Plasmid volume 5 μL 5 μL 5 μL 5 μL
voltage 800 V 800 V 800 V 800 V
time 4 ms 4 ms 4 ms 4 ms

10.11

Colony PCR

YUCHENG ZHANG

Sevral colonies from the plates electroporation were chosen for colony PCR. The result was as follows .One colony from each plate(designated as VCR1-mod, VCR2-mod, VCR3-mod and VCR4-mod respectively.) were chosen for the following experiments.The result was as follows.

pPilin verification 2 × Taq Master Mix 25 μL
ddH2O 20 μL  
CRR+CRF(5 μM) 4 μL  
colony 1  

Whole cell lysates WB for Pilin identification

XIRAN HU

Overnight culture of V.PC was inoculated to the following culture mediums, 20 mL for each condition:

Culturing time\induction concentration 0 20 mM
6 h 1 2

The induction of pilin expression was performed when the OD600 reached 0.5 by arabinose solution. The cultures were maintained at 37 ℃

The primary antibody was diluted at 1:5000 and the second antibody was diluted at 1:5000.