Difference between revisions of "Team:NYMU-Taipei/experimentsandresults"

Line 94: Line 94:
 
<br>
 
<br>
 
<h4>Target</h4>
 
<h4>Target</h4>
<p>To insert CyPet and YPet, which are the fluorescent proteins we use for FRET, into the skeletons that we contructed in Exp1.</p>
+
<p>To insert CyPet and YPet, which are the fluorescent proteins we use for FRET, into the skeletons that we constructed in Exp1.</p>
 
<img src="https://static.igem.org/mediawiki/2018/1/1f/T--NYMU-Taipei--exp2-1.png">
 
<img src="https://static.igem.org/mediawiki/2018/1/1f/T--NYMU-Taipei--exp2-1.png">
 
<img src="https://static.igem.org/mediawiki/2018/0/02/T--NYMU-Taipei--exp2-2.png">
 
<img src="https://static.igem.org/mediawiki/2018/0/02/T--NYMU-Taipei--exp2-2.png">

Revision as of 15:50, 17 October 2018




Cell Model

FRET Model

Exp1. Construction of “The Skeletons”


Target

We aim to replace the Multiple Cloning Site (MCS) of pET32a, which is the plasmid we use for protein expression, with the new MCS that we designed.

Method

  1. pET32a’s MCS was cleaved off and replaced by inserting with FPF-Skel1designed by us. This is the plasmid pET32a FPF-skel1, which was designed to accommodate a DKK1-binding protein fused to the N-terminus of a fluorescent protein.
  2. Polyhistidine tag (His tag), which was synthesized as two single-stranded DNA fragments and annealed by ourselves, was inserted into the new MCS of pET32a FPF-skel1. This is the plasmid pET32a-FPFSkel2, whose new MCS can accommodate a DKK1-binding protein fused to the C-terminus of a fluorescent protein.

Results

Exp2. Insertion of CyPet and YPet


Target

To insert CyPet and YPet, which are the fluorescent proteins we use for FRET, into the skeletons that we constructed in Exp1.

Method

CyPet and YPet, which are amplified by PCR, are inserted into pET32a-FPFSkel1, creating pET32a-FPFSkel1-CyPet and pET32a-FPFSkel1-YPet, respectively.

Results

Exp3. Insertion of DKK1-binding proteins


Target

To insert the nucleotide sequence of DKK1-binding proteins into pET32a-FPFSkel1-CyPet and pET32a-FPFSkel1-YPet, constructed in Exp2.

Method

LRP6BP1, LRP6BP1BP2, LRP6BP3, LRP6BP3BP4, G5(VHH for DKK1), H7(VHH for DKK1) are amplified by PCR and inserted into pET32a-FPFSkel1-CyPet or pET32a-FPFSkel1-YPet or both. Creating a list of new plasmids as follows:

  1. pET32a FPF-Skel1 YPet-Ubc9
  2. pET32a FPF-Skel1 YPet-H7
  3. pET32a FPF-Skel1 YPet-E1E2
  4. pET32a FPF-Skel1 YPet-E3E4
  5. pET32a FPF-Skel1 YPet-E1
  6. pET32a FPF-Skel1 YPet-E3
  7. pET32a FPF-Skel1 CyPet-SUMO1
  8. pET32a FPF-Skel1 CyPet-VHH G5
  9. pET32a FPF-Skel1 CyPet-VHH H7
  10. pET32a FPF-Skel1 CyPet-E3E4
  11. pET32a FPF-Skel1 CyPet-E3

Results

Exp4. Mass Production of Fusion Proteins


Target

To mass produce and purify fusion proteins that will later be used in in vitro DKK1 quantification.

Method

  1. Plasmids constructed in Exp4 are transformed into BL21. BL21 is incubated in flask and induced with lactose or IPTG.
  2. BL21 cell is disrupted and the protein is purified through column.

Results

Exp5. FRET Positive Control


Target

To confirm that we can correctly carry out a FRET experiment.

Method

  1. SUMO1 and Ubc9 are amplified by PCR and inserted into pET32a-FPFSkel1 CyPet and pET32a-FPFSkel1 YPet respectively, resulting in pET32a-FPFSkel1-YPet-Ubc9 and pET32a-FPFSkel1 CyPet SUMO1
  2. The two plasmids are transformed into BL21. BL21 is incubated in flask and induced with lactose or IPTG.
  3. BL21 cell is disrupted and the protein is purified through column, producing SUMO1-CyPet and Ubc9-YPet fusion proteins.
  4. The two fusion proteins are added together with different concentration and ratios in proper buffer and observed with plate readers, with xx being the negative control.

Results

Exp6. Binding check for fusion proteins and DKK1


Target

To make sure that the fusion proteins we produce can bind with DKK1.

Method

HPLC would be carried out on protein samples with fusion protein and DKK1 run individually and added together. The existence of a band shift is considered the sign of binding.

Results

Exp7. Quantification of DKK1


Target

To test if the proteins produce can be used to determine the amount of DKK1.

Method

  1. Two fusion proteins of different FRET pairs would be added into proper buffer with varied concentrations of DKK1 and ratio of the FRET pairs. The buffer without DKK1 would be the control.
  2. The result would be measured by plate readers.

Results

Protocols


E. coli Protocols

Two-day Efficient Cloning Cycle

We used an efficient two-day cloning cycle split into a "Light" day and a "Heavy" day.

Light Day

The light day consists of : Colony PCR and liquid culture of colonies transformed from a previous day.

  1. The 3-in-1

    First, count the number of colonies that you want to check. Then, do the following 3 things sequentially:

    • Liquid culture
    • 2nd time plate
    • Colony PCR

    (Use the same tip to add the template to these three things)

  2. Make The Gel For Electrophoresis
  3. Run Gel Electrophoresis To Check The Colony PCR Product

Heavy Day

The heavy day consists of:

  1. Previously grown plasmid extraction
  2. Plasmid PCR
  3. Gel extraction
  4. Digestion
  5. Ligation
  6. Transformation
Colony PCR (Thermo DreamTaq)
  1. Make the Colony PCR mix (we use Thermo' DreamTaq) with the mix amount slightly modified:
    Item uL
    Primer(Forward and reverse) 1
    dNTP (10mM) 1
    10x DreamTaq buffer 5
    Taq Polymerase 0.2
    ddH20 42.8
    Total 50
  2. Select a colony using a tip or toothpick.
  3. Dip it in a PCR tube and swirl it around.

    PCR run protocol

    Temperature Time  
    94℃ 60s  
    94℃ 15s  
    55℃ 20s 30-35 cycles
    72℃ 1kb/min + 5-10s  
    72℃ 300s  
Liquid culture
  1. Aliquot 4 mL of LB medium in a centrifugal tube for each colony.
  2. Use a tip and dip it in the LB culture and swirls it around.
Draw on 2nd time plate

Take out new plates, for second-time purpose, from the fridge and divide them into smaller sections. Label the date properly. Cross out in red pen if any section is wrong after the Colony PCR is checked.

Making Gel for gel electrophoresis
  1. Make 200mL of gel at a time and select a relevant percentage (e.g. 1%, 1.5%, or 2%)
  2. Measure and calculate the relevant percentage in agarose (e.g. 1g of agarose for 100mL of 1% gel).
  3. Fill it up with 1xTAE buffer.
  4. Microwave in few seconds, constantly taking it out to swirl and mix it each time. Keep radiating until solution turn transparent. Make sure it is completely transparent
  5. Cool down the temperature of solution but make sure there is still a warmness in the flask. If the gel gets too cold and starts to harden, reheat the solution by microwave oven. Make sure it is transparent
  6. Add 5uL of Safe-seeing dye for every 100mL of gel after cooled to the fine tempearature. Mix it well by swirling
  7. Pour it onto the molds quickly. Put a cover on it to block out the light.
  8. Wait at least 15-20 min until using it.
  9. Store in 4°C refridgerator and away from light.
Gel electrophoresis
  1. Select a relevant percentage agarose gel based on your own experience
  2. Load 5uL from each tube of Colony PCR, mix it with 1uL of 6x DNA Dye and put it in a well.
  3. Load 3uL of marker into a well.
  4. Run in the 13x13cm box at 60V or 70V and 400mA for the desired amount of time.
  5. View in the gel viewer machine.
Plasmid Extraction
PCR (DreamTaq or KOD)
Item uL
Primer(Forward and reverse) 0.2
Template(100ng) ?
dNTP (10mM) 0.2
10x DreamTaq buffer 1
Taq Polymerase 0.04
ddH20 to 10 uL
Total 10
Item uL
Primer(Forward and reverse) 0.2
Template(100ng) ?
dNTP (10mM) 0.2
10x KOD buffer 1
KOD Polymerase 0.04
Mg2+
ddH20 to 10 uL
Total 10
Digestion

Insert and backbone:

Item
DNA 600 or 1000ng
10x Buffer 2uL
Enzyme1 0.6 or 1 uL
Enzyme2 0.6 or 1 uL
ddH2O to 20 uL
Total 20

Backbone check:
To check if the backbone is cut.

Item
DNA 100ng
10x Buffer 1 uL
Enzyme1 or 2 0.1 uL
ddH2O to 10 uL
Total 10

Digest for at least 1hr;over 2hr is better. EcoRI doesn't have star activity when cut this way (even overnight)

We run insert digests and backbone digests with backbone check on a gel. Then use GeneAid's gel extraction kit. The modifications in the protocol include:

Warm EB to 60-70℃ before elution.

Always use the Gel (sequencing) protocol for gel extraction.

Ligation

We use Thermo's and NEB's T4 Ligase:

Item amount
Vector 8.5uL, total of approximately 100ng of DNA.
Insert
ddH2O
10x Ligase Buffer 1
T4 Ligase 0.5
Total 10

Incubate at room temperature for 2hr then transform 1uL then put the remaining amount in a small bag and put it in 4℃ overnight in case the transformation fails and retransformation is required.

Transformation

We majorly use commercial E. coli DH5α competent cells and BL21 competent cells we made by ourselves.

  • Add 1uL of plasmid or ligation mix to 20 uL of competent cells.
  • Put mixture on ice for 30 minutes.
  • Heat shock at 42℃ for 1 min.
  • Put the mixture back on ice for another 20 minutes.
  • Add 200 uL of LB broth to repair the cell wall; incubate at 37℃ for 1.5 hr.
  • Plate it on a relevant antibiotic plate.
  • Incubate plate at 37℃ overnight.
Glycerol Stock
Genomic DNA Extraction
Pouring Agar Plates
Preparation of Competent E.coli
Annealing
Protein Purification
Lac operon induction and E.coli cell disruption

Mammalian Cells Protocols

Transfection
HEK293 Culture
Human DKK1 ELISA
Freezing And Thawing Cells
Handling Cells Upon Arrival
Important Considerations For Cell Culture