Team:Harvard/allergy/notebook

From 2010.igem.org

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<div id="abstract">
<div id="abstract">
<h1><a name="notebook">notebook</a></h1>
<h1><a name="notebook">notebook</a></h1>
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<table cellspacing="0" style="text-align:center">
<table cellspacing="0" style="text-align:center">
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<tr><td class="notebook">Week 1</td><td class="notebook"><a class="notebooklink" href="#06-14-2010">06-14-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-15-2010">06-15-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-16-2010">06-16-2010</a></td><td class="notebook"><a href="#06-17-2010">06-17-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-18-2010">06-18-2010</a></td></tr>
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<tr>
-
<tr><td class="notebook">Week 2</td><td class="notebook"><a class="notebooklink" href="#06-21-2010">06-21-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-22-2010">06-22-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-23-2010">06-23-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-24-2010">06-24-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-25-2010">06-25-2010</a></td></tr>
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<td class="notebook">Week 1</td>
-
<tr><td class="notebook">Week 3</td><td class="notebook"><a class="notebooklink" href="#06-28-2010">06-28-2010</a></td><td class="notebook">-</td><td class="notebook"><a class="notebooklink" href="#06-30-2010">06-30-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-17-2010">07-01-2010</a></td><td class="notebook"><a class="notebooklink" href="#06-18-2010">07-02-2010</a></td></tr>
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<td class="notebook"><a class="notebooklink" href="#06-14-2010">06-14-2010</a></td>
-
<tr><td class="notebook">Week 4</td><td class="notebook">-</td><td class="notebook"><a class="notebooklink" href="#07-06-2010" class="notebooklink">07-06-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-07-2010">07-07-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-08-2010">07-08-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-09-2010">07-09-2010</a></td></tr>
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<td class="notebook"><a class="notebooklink" href="#06-15-2010">06-15-2010</a></td>
-
        <tr><td class="notebook">Week 5</td><td class="notebook"><a class"notebooklink" href="#07-12-2010">07-12-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-13-2010" class="notebooklink">07-13-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-14-2010">07-14-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-15-2010">07-15-2010</a></td><td class="notebook"><a class="notebooklink" href="#07-16-2010">07-16-2010</a></td></tr>
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<td class="notebook"><a class="notebooklink" href="#06-16-2010">06-16-2010</a></td>
-
        <tr><td class="notebook">Week 6</td><td class="notebook"><a class"notebooklink" href="#07-19-2010">07-19-2010</a></td><td class="notebook">-</td><td class="notebook">-</td><td class="notebook"><a class="notebooklink" href="#07-22-2010">07-22-2010</a></td><td class="notebook">-</td></tr>
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<td class="notebook"><a href="#06-17-2010">06-17-2010</a></td>
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<td class="notebook"><a class="notebooklink" href="#06-18-2010">06-18-2010</a></td>
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</tr>
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 +
<tr>
 +
<td class="notebook">Week 2</td>
 +
<td class="notebook"><a class="notebooklink" href="#06-21-2010">06-21-2010</a></td>
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<td class="notebook"><a class="notebooklink" href="#06-22-2010">06-22-2010</a></td>
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<td class="notebook"><a class="notebooklink" href="#06-23-2010">06-23-2010</a></td>
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<td class="notebook"><a class="notebooklink" href="#06-24-2010">06-24-2010</a></td>
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<td class="notebook"><a class="notebooklink" href="#06-25-2010">06-25-2010</a></td>
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</tr>
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 +
<tr><td class="notebook">Week 3</td>
 +
<td class="notebook"><a class="notebooklink" href="#06-28-2010">06-28-2010</a></td>
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<td class="notebook">-</td>
 +
<td class="notebook"><a class="notebooklink" href="#06-30-2010">06-30-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#06-17-2010">07-01-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#06-18-2010">07-02-2010</a></td>
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</tr>
 +
 
 +
<tr><td class="notebook">Week 4</td>
 +
<td class="notebook">-</td>
 +
<td class="notebook"><a class="notebooklink" href="#07-06-2010">07-06-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-07-2010">07-07-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-08-2010">07-08-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-09-2010">07-09-2010</a></td>
 +
</tr>
 +
 
 +
<tr>
 +
<td class="notebook">Week 5</td>
 +
<td class="notebook"><a class="notebooklink" href="#07-12-2010">07-12-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-13-2010">07-13-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-14-2010">07-14-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-15-2010">07-15-2010</a></td>
 +
<td class="notebook"><a class="notebooklink" href="#07-16-2010">07-16-2010</a></td>
 +
</tr>
 +
 
 +
<tr>
 +
<td class="notebook">Week 6</td>
 +
<td class="notebook"><a class="notebooklink" href="#07-19-2010">07-19-2010</a></td>
 +
<td class="notebook">-</td>
 +
<td class="notebook">-</td>
 +
<td class="notebook"><a class="notebooklink" href="#07-22-2010">07-22-2010</a></td>
 +
<td class="notebook">-</td></tr>
</table>
</table>
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Revision as of 16:20, 22 October 2010


notebook

Week 1 06-14-2010 06-15-2010 06-16-2010 06-17-2010 06-18-2010
Week 2 06-21-2010 06-22-2010 06-23-2010 06-24-2010 06-25-2010
Week 3 06-28-2010 - 06-30-2010 07-01-2010 07-02-2010
Week 4 - 07-06-2010 07-07-2010 07-08-2010 07-09-2010
Week 5 07-12-2010 07-13-2010 07-14-2010 07-15-2010 07-16-2010
Week 6 07-19-2010 - - 07-22-2010 -


06-14-2010 [top]
Started preparation of agrobacterium vector backbones
  • Digested O1, O2, E3, E4, R1, R3 with HindIII and SpeI (Fast Digest Protocol - make link)
  • Ran digests on 1% agarose gel (protocol link)
  • Digest successful for O1, O2, and R1 but not for E3, E4, and R3 (reason unknown)
  • Cut out backbone (top) bands from O1, O2, R1 and saved them at 4°C
06-15-2010 [top]
Continued preparation of agrobacterium vector backbones
  • Re-digested E3, E4, R1, R3 with HindIII and SpeI (Fast Digest Protocol - make link)
  • Digest successful for all reactions
  • Cut out backbone (top) bands for E3, E4, R3 from the gel
  • Realized that ordered O1, O2 oligos had SacII sticky and rather than HindIII
  • Re-digested O1, O2 with SacII and SpeI to prepare backbone with the correct sticky ends (regular digest protocol, buffer 4)
  • Ran digests on 1% agarose gel (protocol link)
  • Digest successful for both reactions
  • Cut out backbone bands for both reactions
  • Annealed open series insert oligos (synthesized by Mr. Gene) (protocol link - karmella's)
  • Gel purified bands for all reactions (protocol link)
  • Realized that backbones needed to be dephosphorylated before ligation, so redid digestions with phosphatase.
  • Digested O1, O2 with SacII and SpeI, with TSAP (phosphatase) added (slow digest protocol, buffer 4, 30 ul reactions). Did two digest reactions for each vector to increase yields.
  • Digested E3, E4, R1, R3 with HindIII and SpeI, with TSAP added (fast digest protocol, 30 ul reactions). Did two digest reactions for each vector to increase yields.
  • Ran digests on 1% agarose gel (protocol link)
  • Digest successful for all reactions
  • Cut out backbone (top) bands for each reaction, keeping the two digests of each vector in the same eppendorf tube.
06-16-2010 [top]
Completed preparation of agrobacterium vector backbones and prepared expression series and reporter series inserts
  • Gel purified digest slices from previous day (protocol link)
  • Ran a PCR reaction on E3, E4, R1, R3 vectors with primers synthesized by Mr. Gene (PCR phusion protocol) to generate inserts
  • Melting Temperature: 60°C
  • Elongation Time: E3, E4, R3 (~0.6 kb) - 15 seconds; R1 (~2 kb) - 30 seconds
  • Ran part of each reaction on 1% agarose gel to determine if correct products were formed
  • PCR reactions were successful
  • PCR purified remainder of each reaction
  • Digested PCR products to prepare products with correct sticky ends (two digests per vector)
  • Digested with HindIII and SpeI (Fast Digest Protocol, 20 ul reactions)
  • Ran on 1% agarose gel (protocol)
  • Cut out insert (top) bands for each reaction, keeping the two digests of each product in the same eppendorf tube.
  • Gel purified products (protocol)
06-17-2010 [top]
Ligated digested backbones and inserts. Transformed and plated on LB and Kanamycin.
  • Prepared LB plates with 50 ug/ml kanamycin (15 ug of kanamycin per plate)
  • Prepared 50 ug/ml LB+Kan Media.
  • Ligated backbones and inserts of expression and reporter series vectors (ligation protocol)
  • Used 50 ng of digested, dephosphorylated backbone DNA
  • Used roughly 3x molar excess of digested vector
  • Mass of Insert = [Size of Insert][Molar excess][Mass of Vector]/[Size of Vector]
  • Size of Agrobacterium vector backbone: ~7 kb
  • VectorInsert SizeInsert Mass
    E3600 bp13 ng
    E4600 bp13 ng
    R12000 bp20 ng
    R31000 bp40 ng
  • Transformed ligation reactions into TURBO e. coli cells (protocol)
  • Transformed 5 ul of reaction mix into 15 ul of cells
  • Plated onto LB + Kan plates, left at 30°C overnight
06-18-2010 [top]
Realized that there was a 1bp error in annealed oligos for O1 and O2 (had sticky end for SpeI site instead of NheI site)
  • Ordered new oligos with corrected bp
Started to obtain E3, E4, R1 and R3 plasmids from E. coli
  • Prepared 50 ug/ml LB+Kan Media.
  • Picked four colonies of E. coli from the E3, E4, R1 and R3 plates and made a culture from each in LB and Kanamycin
  • Left cultures at 37°C for 6 hours
  • Centrifuged cultures to produce pellet and removed the liquid
  • Stored pellet at -20°C
06-21-2010 [top]
Carried out initial test to verify the identity of plasmid transformed into E. coli
  • Carried out miniprep to obtain plasmids from cells (protocol link)
  • Digested plasmids with EcoI and HindIII (protocol link)
  • Ran digests on 1% agarose gel (protocol link)
  • Ladder was unclear so needed to repeat
  • Measured concentration of miniprep product
  • Concentrations were low (<44ng/uL) so needed to redo miniprep
  • Picked new colonies (2 from each plate) and grew cultures overnight
06-22-2010 [top]
Continued to carry out initial test to verify the identity of plasmid transformed into E. coli
  • Carried out miniprep to obtain plasmids from cells (protocol link)
  • Digested plasmids with EcoI and HindIII (protocol link)
  • Ran digests on 1% agarose gel (protocol link)
  • Larger bands were observed, suggesting the correct backbones were present
  • Smaller bands were observed, suggesting the correct inserts were present
Started to prepare for plasmids to be sequenced
  • Required more plasmids
  • Transformed plasmids back into E. coli using heat shock (carried out twice for each of V9-12) (see protocol)
  • Added Kanamycin to LB plates
  • Spread E. coli cells onto LB + Kanamycin plates
  • Left plates in 37°C overnight
06-23-2010 [top]
Continued to prepare for plasmids to be sequenced
  • Picked 3 colonies from each of the V9, V10 and V12 plates and 4 colonies from each of the V11 plates
  • Left at 37°C for 6 hours
  • After 6 hours, had not grown enough, so left cultures overnight at 37ºC
06-24-2010 [top]
Miniprepped V9-V12 cultures. Got yields with enough DNA to send to GeneWiz for sequencing. Primers arrived from Mr. Gene and we will send constructs off for sequencing next week.

Started putting together Open Series constructs

  • Annealed oligos synthesized by Mr. Gene to form insert (protocol)
  • Ligated with backbone digested last week
  • Transformed into TURBO E. Coli and plated onto LB + Kan
06-25-2010 [top]
Continued preparation of Open Series constructs
  • Picked colonies from both V7 (O1) and V8 (O2) and set up cultures. Only cultures for V7 grew. Because of the patterns of colonies on the plates, we suspect that the Kanamycin was not properly spread on the plates.
  • We had used up all of our remaining digested backbone for O2, so we redid the SacII/SpeI digestion on both vectors with phosphatase, re-ligated, and re-transformed and plated, using a negative control
06-28-2010 [top]
Completed preparation of Open Series construct
  • Colonies grew for V8 (O2) only. Set up cultures for colonies.
  • Miniprepped cultures of both constructs
Prepared vectors for sequencing
  • Resuspended primers in water
  • Mixed required quantities and concentrations of each vector and primer in PCR tubes
  • Sent tubes to GeneWiz for sequencing
06-30-2010 [top]
Got back sequencing results (link to sequences)
  • Confirmed V9, V10, V11, V12 - both #5,6 for all. V11 had a single base pair change in the middle of the GusA sequence (bp 6315, T instead of C). This basepair is at the end of a codon, and the change does not change the translation of the sequence.
  • V7, V8 had faulty primers - the reverse was not the reverse compliment and the forward was too close to the sequence, so redesigned primers and ordered them.
07-01-2010 [top]
Started to produce more of the V9-V12 vectors
  • Set up starter cultures for V9-V12 for maxipreps from colonies from the #5 plate of each construct (in LB+Kan 50ug/ml)
  • Poured started cultures in 150mL LB + Kan (50ug/ml)
Tested transformation into agrobacterium
  • Agrobacterium transformation (electroporation)
  • Transformed E4 and V10, plus did a control that was shocked without DNA, and a control that was not shocked but had E4 in it.
  • Plated on LB+Kan(50ug/ml) + Gent(30ug/ml) + Rif(10ug/ml)
07-02-2010 [top]
  • Carried out maxipreps of V9-V12
  • Created glycerol stocks of V9-V12
07-06-2010 [top]
  • Agrobacterium plates had colonies for E4 and V10 and no growth for the negative controls
  • Sequencing V7 and V8 showed they were correct (see sequences)
  • Started cultures for maxiprep of V7 and V8
07-07-2010 [top]
  • Carried out maxipreps of V7 and V8
07-12-2010 [top]
  • Started putting finished constructs from other teams into vectors
  • Digested V9, V10, Miraculin, Brazzein, Miraculin + YFP, Brazzein + YFP with EcoRI and PstI (V9/V10 with TSAP added as well)
  • Digested parts appear to be the correct size
  • Gel extraction led to low yields, so redid digestions the next day
07-13-2010 [top]
  • Continued putting finished constructs into vectors
  • Digested V9, V10, Miraculin, Brazzein, Miraculin + YFP, Brazzein + YFP, GFP Knockdown 1, GFP Knockdown 3 with EcoRI and PstI (V9/V10 with TSAP added as well)
  • Digested parts appear to be the correct size
  • Ligated vectors (V9/V10) and inserts to form V21-V32 (see parts page) and transformed into TURBO E. coli
07-14-2010 [top]
  • Colonies from 7-13-10 transformation were very large and unevenly spread
  • Picked two colonies from each ligation and started cultures
07-15-2010 [top]
  • Miniprepped cultures for V21-V32 (set up 7-14-10)
  • Transformed into Agrobacteria
  • Settings: Agr Setting on electroporator
  • Amounts: 40 ul electrocompetent cells, 5.5 ul DNA (~100 ng/ul)
  • Transformed: V21-V32 #2, V10 as positive control, blank cells as negative control
  • Plated transforms onto LB + Kan + Rif + Gent plates
07-16-2010 [top]
  • Confirmation digest on V21-V32 #1,2
  • All constructs had inserts of the correct size, except V23-2
07-19-2010 [top]
  • Set up lawn plates on YEB + Kan + Gent + Rif
  • V21-V32 except V23, V10, E4 (from prior transform)
  • Resuspended each individual colony in 30 ul water, plated 25 ul of resuspension (5 ul kept for sequencing)
07-22-2010 [top]
  • Removed lawn plates from incubator in the morning
  • E4 did not grow as much, so left it in the incubator (the colony picked to make the plate was older than the others)

Procedures

Gel Electrophoresis

Today, we loaded gel slots to run our 6 DNA samples against a 1kb ladder. The order of our slots were: ladder, ladder, sense 1, sense 1, sense 2, sense 2, sense 3, sense 3, antisense 1, antisense 1, antisense 2, antisense 2, antisense3, and antisense 3. We had to load two slots because there was more than 50 microliters of DNA and it would not fit into one slot. Since we are hoping to collect and purify the DNA after the electrophoresis, we want to run as much of the sample as possible. We also loaded two ladders. We ran the gel for 30 minutes at 100 volts. Our goal is to have the majority of the amplified DNA to be 300bps long.

Thirty minutes later, we examined our gel under UV light. All of the DNA were smaller than 100bp, suggesting that the Phusion Polymerase did not amplify the correct DNA segment. Our sample looks like a primer dimer.

Results

If our Phusion Polymerase had worked, then we would have continued to extract the correctly formed DNA segments, performed a restriction digest and cut the PCR products into a B0120 biobrick with Xba1 and Pst1, ligate, and transform into E. coli. However, since we do not have the correct DNA, we cannot move forward.

Errors

There are several reasons for why our gel did not work. The most likely reasons is that the RNA extraction did not work properly. We used strawberry fruit as our sample for RNA extraction. Because RNA is constantly being degraded by RNAases, the integrity of our RNA may have been compromised before the addition of the denaturant.We will re-extract DNA from our plant samples, now including arabidopsis, probably tomorrow.

Another potential error could have occurred during the Phusion Polymerase. We set our annealing temperature at 72°C, which could have been too high for three of our four primers. We'll rerun our PCR with a gradient PCR of annealing temperatures to see if we can get a better result. The amount of DNA added by template was also much higher than the optimal 50~250 nanograms per 50 micrograms of PCR reactants. We will dilute the DNA templates to 100 micromolar and use one microliter per reaction so that there are approximately 100 nanograms of DNA per reaction.


The Next Step...

Corrections

Redo gel electrophoresis with all three concentrations of Antisense and Sense, each at a range of temperatures, from one to three degrees Celsius above the lower annealing temperature of the primers. This will give three tubes of each of three concentrations of both Sense and Antisense, for a total of 18 tubes. Run gel for 30 minutes at 100 volts with a 100kb ladder.

Corrections were unsuccessful. We are going to go further back and do more research on the strawberry allergen and see if we can obtain a better RNA and DNA sample.

Strawberries are also non-climacteric fruits, which means that they cease to respire after being picked. Our sample strawberries were picked from a grocery store, so whatever mRNA responsible for ripening would have degraded after picking. Climactic fruit, like tomatoes and apples, continue to metabolize sugars and ripen after being picked. The mRNA we were hoping to obtain is related to the ripening process of strawberries, but since our strawberries were not fresh, it is possible that all of the mRNA responsible for coding Fraa1 had degraded before our RNA extraction was performed.

Further procedures If the gel electrophoresis is successful and the pieces are 300bps, then we will perform:

  • Gel Extraction - remove the correct Antisense and Sense DNA segments
  • Restriction Digest - cut the DNA segments with Eco1 and Xba1 (keeping A and S separate)
  • Ligation - links sense, intron, and antisense into a V0120 plasmid (Biobrick)
  • E. coli Transformation - insert the plasmid into bacteria