Penn State iGEM 2014 Notebook Page
Here you will find weekly summaries of our wet laboratory progress, team updates, and accomplishments outside the laboratory. Below [link this] is our detailed, day-to-day progress laboratory notebook.
Weekly Summaries
will create links to each week, but will just list down the page Week 1, Week 2, etc etc
Laboratory Notebook
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Biodetoxification |
Codon Optimization |
| Tuesday, May 20, 2014 |
First iGEM meeting with Dr. Richard and Dr. Salis. |
First iGEM meeting with Dr. Richard and Dr. Salis. |
| Wednesday, May 21, 2014 |
Emily's first experience with cloning! Ashlee led Emily through several practice experiments from designs made earlier in the year: making a gel, loading samples, gel purifying DNA. |
Clay and Sam worked on a program in Excel to codon optimize GFPs. Sucess. Unfortunately, program is clunky and requires a lot of user input for any optimization. Decision made to attempt the same task in MATLAB. |
| Thursday, May 22, 2014 |
Ashlee and Emily performed a transformation. |
RBS design begun. Library calculator run using 34 N's as a constraint in the "Constraints" field. Nothing used in pre sequence field. First 60 bp of original superfolder GFP used as "coding sequence". Clay started working on MATLAB program for codon optimization. |
| Friday, May 23, 2014 |
We picked several colonies for overnight growth to do more cloning tomorrow. |
Design of GFPs continues as Clay works on program to optimize genes. Question asked: which GFP should be optimized? GFP mut3b and superfolder GFP both present advantages and disadvantages. Met with Chiam Yu to discuss effects of codon optimization on translation. Acquired data from previous codon optimization project, which will serve as the basis for our fast/slow codon optimization. |
| Saturday, May 24, 2014 |
Memorial Day Weekend? How about lab cloning weekend! Ashlee conducted plasmid preparation and digestion. |
More RBS library calculations run. Problem: since TIR is dependent on the first 60 bp of a coding sequence and our variant GFPs will differ in this region, how can we ensure that an accurate library is developed? |
| Monday, May 26, 2014 |
Due to a string of failed clonings with the broadhost vector pSEVA251 and the large inserts, new designs are evaluated! Instead of creating a plasmid with the HMF pathway (7.5 kb) and dCas9 system (5.5 kb), we shall add the HMF pathway and dCas9 to the P. putida genome using homologous recombination. |
Decision reached to optimize Superfolder GFP based on its superior post translational modification, ensuring that translation elongation remains the rate limiting step. Papers on codon optimization downloaded to Mendeley Desktop. New hypothesis for existence of rare codons developed: Perhaps they function as a molecular "brake" to slow down translation and prevent "ribosome traffic jams." |
| Tuesday, May 27, 2014 |
Inoculated LB broth with ampicillin and dCas9 plasmid from cryogenic storage; inoculated Lb broth with chloramphenicol and FTV vector from Ashlee's past experiment; streaked the HMF vector on a kanamycin plate. |
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| Wednesday, May 28, 2014 |
Emily and Ashlee made cryogenic storage of the dCas9 plasmid; plasmid prepared the FTV and dCas9 vectors; digested FTV vector; inoculated LB broth with a colony from the HMF plate for overnight growth and plasmid preparation tomorrow. |
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| Thursday, May 29, 2014 |
Prepared plasmid containing the HMF pathway; inoculated LB broth with Lambda Red Recombinase plasmid from cryogenic storage. Ashlee, Emily, and graduate student Iman Farasat ordered primers for three plasmids that will be constructed via Gibson Chew-Back and Annealing Assembly, two of which will be inserted into the genome by homologous recombination. |
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| Friday, May 30, 2014 |
Ashlee and Emily made cryogenic storage of the Lambda Red Recombinase plasmid. |
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| Monday, June 2, 2014 |
Constructed dCas9 gene cassette and plasmid backbone with replication origin ColE1 via PCR Rescue. Gel purified dCas9 and ColE1 cassettes. 1 out of 4 dCas9 PCR's were successful, and 2 out of 4 colE1's were successful, all of which were Ashlee's. We attributed this to Emily's lack of cloning experience. |
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| Tuesday, June 3, 2014 |
Conducted Colony PCR using P. putida KT2440 strain as DNA template to construct two ~1 kb genome overlaps. Plasmid prepared the Lambda Red Recombinase plasmid, DH10B-PKD46, FTV-ptac-LacI-CmR plasmid, and NoHP_15A_Plmra_CmR plasmid containing RFP with a strong, unique promoter. Stock of NoHP_15A_Pkmra_CmR and FTV_ptac_LacI_CmR for cryogenic storage was also made. Lambda Red Recombinase cassette was amplified using PCR Rescue and gel purified. |
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| Wednesday, June 4, 2014 |
We made ampicillin agar plates and ampicillin antibiotic stock for cloning. The PCR Rescue of Lambda Red Recombinase was also gel purified. |
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| Thursday, June 5, 2014 |
We conducted PCR Rescue to amplify the kanamycin resistance cassette (specifically the neomycin cassette, which also confers resistance to kanamycin) from pSEVA251 KanR plasmid. Two different sets of primers for kanamycin were tested, and the first set was successful - all 4 PCR's were correct. The second set of primers all failed. However, Emily had her first PCR success! Kanamycin cassette was gel purified. |
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| Friday, June 6, 2014 |
Conducted colony PCR using P. putida KT2440 strain as the DNA template to construct 1 kb overlaps for homologous recombination. All four of the first genome overlaps with gene PP_0747 were successful; only 2 overlaps with upp gene were successful. These were gel purified. We learned Gibson Chew-Back Annealing Assembly (CBA) protocol. |
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| Sunday, June 8, 2014 |
One 4-part, two 3-part, and two 2-part Gibson CBA's were conducted to assemble the kanamycin resistance cassette, two genome overlaps, and the colE1 replication origin. This completed plasmid will be termed "plasmid 1". |
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| Monday, June 9, 2014 |
The two 2-part and two 3-part CBA's were amplified using PCR Rescue and gel purified. The original 4-part CBA was transformed into E. coli electrocompetent cells using electroporation and plated on kanamycin antibiotic agar plates. The 4-part CBA was repeated to ensure accuracy. Because the CBA parts contained no plasmid DNA, the 4-part CBA could be digested by restriction enzyme Dpn1. Dpn1 binds and cuts methylated DNA sites, thus destroying any plasmid DNA remaining as a contaminant. |
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| Tuesday, June 10, 2014 |
The original 4-part CBA worked! Many colonies appeared on the plate after incubation at 37 degrees C for 18 hours, and 12 colonies were selected for plasmid preparation. These were digested with AatII and XbaI, two restriction sites that are only both contained in the final assembled 4-part plasmid. 6/12 colonies showed the correct bands on the gel. We also prepared more 1 kb ladder from concentrate. |
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| Wednesday, June 11, 2014 |
3 successful colonies were sent for sequencing. In order to insert the dCas9 system into plasmid 1, dCas9 was digested with XhoI and ClaI. 4 successful colonies were digested with ClaI for 3 hours, heat inactivated at 65 degrees C, and then digested with SalI-HF restriction enzyme. SalI and XhoI are compatible sites. These digestions were gel purified, resulting in low concentrations of plasmid DNA. Only two colonies were used to continue further. We met with Leah Bug and Matthew Johnson from the Penn State Center for Science and the Schools. |
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| Thursday, June 12, 2014 |
The plasmid backbone was digested with phosphotase enzyme. These backbones were ligated to dCas9 over 18 hours at 16 degrees C to ensure maximum ligation product. |
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| Friday, June 13, 2014 |
Emily purified the ligation product. |
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| Sunday June 15, 2014 |
Ashlee transformed the ligation into E. coli DH10B electrocompetent cells via electroporation, and plated them on kanamycin antibiotic agar plates to grow overnight. |
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| Monday, June 16, 2014 |
The ligation failed. We amplified more of the dCas9 system using PCR Rescue, in which 2 out of 4 PCR's were successful - both Emily's!. We are evaluating this difficult PCR and will be altering the annealing temperature. PCR Rescue for dCas9 were repeated at 58 degrees C and 62 degrees C annealing temperature. We inoculated LB broth with ampicillin resistance and dCas9 from cryogenic stock. We also conducted colony PCR of the second set of genome overlaps. We received our sequencing results and two out of three colonies have the correct sequence. |
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| Tuesday, June 17, 2014 |
PCR Rescue RFP cassette and gel purified - all 4 RFP PCR's worked. Gel purified dCas9 Rescue from yesterday. PCR Rescue colE1 origin and chloramphenicol resistance cassette to construct plasmid 2, which will contain ColE1, CmR, RFP, HMF pathway, and two P. putida genome overlaps. We plasmid prepared new dCas9 to use as a template for PCR. New and old dCas9 templates were used for PCR Rescue of the third genome overlap. See the schematic here for more information. |
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| Wednesday, June 18, 2014 |
Digested the HMF pathway with EcoRI-HF and PstI-HF restriction enzymes. All PCR's of the third genome overlap containing dCas9 failed, and we realized we must complete the first plasmid by inserting dCas9 and use that as a template instead of the original dCas9 plasmid. This points the failure of the ligation to either the dCas9 PCR's or the ligase buffer has expired. We made new aliquots of fresh ligase buffer to test whether this was the case. We have run out of ClaI and cannot digest dCas9 until this arrives. Our strategy now is to Gibson assembly the Lambda Red Recombinase system and dCas9, then PCR Rescue and ligate into plasmid 1 using XhoI/SalI-HF and XbaI to mitigate the lack of ClaI. |
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| Thursday, June 19, 2014 |
Conducted 2-part Gibson CBA to assemble the Lambda Red Recombinase system and the dCas9 system. |
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| Friday, June 20, 2014 |
PCR Rescue to amplify Lambda Red Recombinase and dCas9 cassette and gel purified. Gel bands reflect failed Gibson CBA. |
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| Monday, June 23, 2014 |
Repeat Gibson CBA of Lambda Red Recombinase system and dCas9 cassette using 25 femtomole DNA and 50 femtomole DNA. Emily and Ashlee worked on the presentation to the teachers for the Center for Science and the Schools. |
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| Tuesday, June 24, 2014 |
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| Wednesday, June 25, 2014 |
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| Thursday, June 26, 2014 |
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| Friday, June 27, 2014 |
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| Saturday, June 28, 2014 |
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| Sunday, June 29, 2014 |
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| Monday, June 30, 2014 |
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| Tuesday, July 1, 2014 |
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| Wednesday, July 2, 2014 |
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| Thursday, July 3, 2014 |
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| Friday, July 4, 2014 |
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| Saturday, July 5, 2014 |
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| Sunday, July 6, 2014 |
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| Monday, July 7, 2014 |
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| Tuesday, July 8, 2014 |
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| Wednesday, July 9, 2014 |
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| Thursday, July 10, 2014 |
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| Friday, July 11, 2014 |
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| Saturday, July 12, 2014 |
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| Sunday, July 13, 2014 |
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| Monday, July 14, 2014 |
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| Tuesday, July 15, 2014 |
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| Wednesday, July 16, 2014 |
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| Thursday, July 17, 2014 |
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| Friday, July 18, 2014 |
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| Saturday, July 19, 2014 |
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| Sunday, July 20, 2014 |
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| Monday, July 21, 2014 |
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| Tuesday, July 22, 2014 |
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| Wednesday, July 23, 2014 |
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| Thursday, July 24, 2014 |
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| Friday, July 25, 2014 |
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| Saturday, July 26, 2014 |
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| Sunday, July 27, 2014 |
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| Monday, July 28, 2014 |
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| Tuesday, July 29, 2014 |
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| Wednesday, July 30, 2014 |
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| Thursday, July 31, 2014 |
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