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Team:Penn State/Research
From 2011.igem.org
Achievements
We did lots of great things! Check it!
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Registered Team, had (too much) fun throughout the summer |
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Plan to attend the Jamboree and present our results |
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At least one submitted and characterized part |
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Demonstrated part works as expected |
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Characterized one new part and entered the data in the “Main Page” section of that Part’s/Device’s Registry entry |
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Worked towards improving the function of an existing BioBrick Part |
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Helped another team (see our collaboration with NYC wetware below!) |
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New approach to human practices (Watch our Human Practices Video and learn about our workshop here) |
Experimental Results
Testing of Or as a Promoter
The backbone of the radiation sensor in our project relies on the operating region Or, and the two promoters one on each end of Or. In order to test the function ability of the of the pr promoter we attached a part called mcherry, which has rfp to the promoter. We used the TECAN in our lab to measure the fluorescence of our samples over time. The data collected while the samples were in exponential growth was used to determine a rate of expression of the rfp. Compared to the control, the rate of fluorescence was much higher in our test subject, about 4227 compared to 418 (fu/OD600nm). This suggests that the promoter on Or is functional.
Future Testing
Much of the work our project is still underway and due to time constraints cannot be posted before wiki freeze deadline. More characterization and testing of all the parts we are actively building is on the way and should be accomplished by the Jamboree.See our project pages for more information.
Dosimeter Design
After genetically modifying Escherichia coli to perform the task of acting as a bacterial dosimeter, we started looking into designs for building the actual device. After taking a tour of our Nuclear Reactor Facilities on campus, we were introduced to a wide variety of dosimeters already in use in the building. We designed our device to focus on three main points: portability, durability, and reliability. The dosimeter was designed in an octagonal shape for aesthetics with a shear 5 cm diameter and a width of 1 cm. These parameters allow for a light, portable device. Another idea we used in designing the device with the belief that it should be reusable. For this reason, the device is designed in a camera and film pairing. The hollow case made out of a hard plastic, or in case of the analogy the “camera”, is designed to be durable and reusable, while the tray will be for one-time use.
After use the tray will be developed in catechol, etc. to show the different levels of radiation presents. The dosimeter tray will have a thin layer a gellan gum, as developed by BCS Bristol’s iGEM team in 2010, but instead of being made into balls we will use a thin sheet of gellan gum instead. Our modified Escherichia coli, will be living in this gel will be tested by exposing it to gamma radiation at our nuclear reactor on campus. The trays can be kept in the -80 degree Celsius freezer for long term storage.
Collaboration
Throughout the summer we connected with other iGEM teams interested in radiation-related projects. The NYC Wetware team in particular was studying the effects of genes cloned from the organism Deinococcus radiodurans on radiation resistance in E.coli. We were given the honor of helping them characterize one of their strains TS TR, a strain capable of producing the molecule trypanothione.
Using the gamma facilities provided by the Radiation Science and Engineering Center at Penn state we were able to carry out tests of gamma irradiation of their strain and subsequently measure cell viability.
Aliquots of culture (5ml each) inoculated with the TS TR strain were added to tubes which were irradiated by a cobalt-60 gamma source at a dose rate of 25 gys/min for total doses ranging from 0-800 gys. After irradiation 0.02 ml of the irradiated sample was inoculated into 5 ml of SOB media. The OD600 was measured 12 hours later. The results are shown below.
