Week 1
In the first week we began constructing basic reporter DNA constructs that have various combinations of promoters and genes. The mix-and-matching of promoters and genes was done using the LR reaction following the Gateway protocol. Our promoters included TRE, minCMV, Hef1a, Hefl1a-LacO, and our genes included eYFP, mKate, and eBFP2. Transformed and inoculated colonies from the LR reactions and performed restriction digests. Approximately half of the LR reactions were successful and became DNA parts that we could use later on.
Week 2
In the second week we attempted midipreps instead of minipreps of our available cell stocks. Midipreps were unsuccessful, likely due to centrifuge limitations. LR reactions to generate more usable promoter-gene pair parts continued, expanding to include the CI434-VP16, LexA-VP16, and Mnt-VP16 genes, whose expressed proteins activate the appropriate corresponding minCMV promoters. Most of the LRs done were not successful, reason unknown at this time.
Week 3
In the third week we continued expanding our library of usable DNA parts by creating more combinations of genes and promoters using the LR reaction.
Week 4
In the fourth week we implemented a color-coded box system in our -20 freezer to accommodate for the growing need of organization of the growing number of DNA parts. We began learning and using the Gibson reaction to create the gene part AVPR2-TEVs-GV16, which is expressed to produce a vasopressin receptor bound to Gal4-VP16 by a TEV sequence that can be recognized by the TEV Protease. Gibson reaction results were not great, and it appeared that our AVPR2 DNA was not of sufficient quality, so we re-PCRed the AVPR2 DNA segment.
Week 5
We began looking into using the Goldengate assembly method, but two gene elements contained a cut site that needed to be mutated out. We performed Site-Directed Mutagenesis using the Lightning Kit in the hopes of mutating out the cut site, but results were not successful due to mishandling during the protocol, so the procedure was set to be repeated. Gibson assembly of AVPR2-TEVs-GV16 continues as we re-PCRed the AVPR2 DNA segment and re-run the entire Gibson protocol, picking 20 colonies in a determined attempt to obtain a successful result.
Week 6
In the sixth week we continued re-attemping previous failures using modified protocols or higher quality DNA in hopes of obtaining successful reactions. We also began looking at Cadherins and the possibility of using them as a clumping mechanism for mammalian cells. In order to visualize Cadherins, we needed some sort of fluorescent color, so construction of NCadherin-EGFP (NCadherin is one of many types of cadherin) began. DNA for NCad-EGFP was ordered, but needed to be in a format such that we could LR react it with the different promoters we have. This is done by attaching attB sites to flank the NCad-EGFP gene and then performing the BP reaction, which generates LR reaction-compatible parts. PCR of the attB sites was successful. By this week we have also begun work with mammalian cell cultures. To explore the limitless possibilities of synthetic biology, a few of us took it upon themselves to look into other interesting gene components, such as the Caspase gene and the FF4 tag.
Week 7
Part of the team worked on creating protocols for a robot liquid handler to run the usual lab reactions that we run. We are hoping that the robot can replace us and do our liquid-related lab work for us. Various dry test runs were done. We transfected various DNA parts that we have into Hek293 cells, and results show that most of our DNA works. We investigated the TRE-rtTA3 system as well as the UAS-Gal4 system. Both seemed to be functional.
Week 8
This week we underwent a momentous drive to create more LRs. A large list of promoter-gene pairs was conceived of and we began to run through LR reactions in somewhat of a factory manner. This occupied much of our time. We also received and prepared DNA parts from Elowitz's group in Caltech. We also got trained on using the FACS machine and began to get quantitative data on our transfections.
Week 9
In the ninth week we did a lot of internal re-organization to increase our overall efficiency in work. This involved re-organizing an internal wiki that we use for management of our available DNA as well as a log of transfections needed to be done. Lots of samples were FACS-ed, generating lots of results that we can make graphs out of. Many of our parts were successfully characterized.
Week 10
Computer simulations of the Notch-Delta interactions were presented in our group this week, and we became convinced of the possibility of creating self-patterning mammalian cells. On the DNA side of things, we are trying to create more and more DNA using miniprep, because midipreps have for some reason not been successful for us or the 2010 iGEM team. On the transfection side, a lot of new DNA parts were transfected, observed under the microscope, and FACS-ed to quantify their effect/behavior.
Week 11
In our experimental attempt to characterize the Notch-Delta interaction, we used co-culture of CHO and Hek293 cells as well as stable cell lines of Notch-containing and Delta-containing cells from Elowitz to observe the trans-activation of Notch by Delta. Other experiments using CHO cells, which are more difficult to transfect than Hek293 using Lipofectamine, were carried out to observe the behavior of CHO transfected cells.
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