|Home||Team||Official Team Profile||Project||Parts Submitted to the Registry||Modeling||Notebook||Safety||Attributions|
Arsenic is a poisonous metal that occurs naturally in ground water and can also be concentrated in industrial and agricultural areas. It is odorless and tasteless so people can consume it without knowing it. Arsenic can build up in the body and lead to health problems. We decided to use a synthetic biology approach to build an iGEM biosensor we call "Winterkist, Heavy Metal Detector" that could be used to detect exact levels of arsenic in a laboratory and also have a warning system in it that alerts people who want to test water but don't have access to laboratory equipment. To do this we made one composite part that joined an arsenic-sensitive promoter, BBa-190015, with a GFP-generator, BBa_E0480 so that greater arsenic levels could be detected by a stronger glow in a fluorimeter. In another composite part we joined the arsenic-sensitive promoter to a wintergreen smell generator, BBa_J45119. If arsenic contaminated water is placed with our Winterkist detector and salicylic acid, the combination will make a wintergreen smell warning someone not to drink the water. In the lab we were successful in building both composite parts and joining them into a single device. We have had a difficult time characterizing the device's ability to detect arsenic in either way. We can show in a control experiments that arabinose stimulates the fluorescence of GFP under the control of ARA-C in the pGLO plasmid (Bio-Rad) so we know that we should be able to detect it if it is working. We have more work to do.
We pulled all of our parts from the Registry of Standard Parts 2011 Distribution and transformed InVitrogen E.coli. Top 10 cells with 1 uL each using the chemical method of transformation (CaCl2 from BioRad). We selected for the transformed bacteria on LB agar plates with the antibiotic ampicillin (50 ug/uL). We chose the largest colonies and started broth culture in LB-AMP broth. After overnight growth the cultures were cloudy and we spun down the bacteria in a centrifuge and purified the plasma DNA with spin columns (from BioRad)