User talk:Jelena

From 2006.igem.org

Revision as of 15:57, 3 July 2006

I'm just gonna stick up random project notes here, since they're easier to access and move around if they happen to be online already.

I think the most promising version of the arsenic biosensor is the second one, combining an acid and an alkali output. Now, the preliminary tests for this that need to be done are as follows:

• Experiments with different copy numbers of the arsenic sensor, to see if it's possible to develop sensors of different sensitivities

Without genetic modification:

• The pH of urea in solution
• The pH of lactose and urea in solution mixed together
• The change in pH when urea is digested by urease
• The change in pH when urea is digested by urease and lactose is present
• The change in pH when lactose is digested by lacZ when urea is present

With genetic modification:

We would hopefully have the lacZ system already from the simpler arsenic setup. So that's Device 3 sorted, but we need to engineer functioning Devices 1 and 2.

• Device 1: Sticking urease onto the end of the lac regulatory region. This shouldn't be a problem, as the regulatory region is available, and the whole thing is a reasonably simple procedure. We'd need to find out if it works, but hopefully...
• Device 2: This part is likely to be a nightmare. We'd have the arsenic sensor available from previous experiments, but we need to find a repressor that would completely neutralise the effects of the expressed urease. There's a number of ways of doing this, but it's likely to be kind of fiddly. It might be an idea to first engineer Device 1, then try it out by just putting in different repressor molecules manually into the sample to see which ones work best, and only then going on to genetically engineer the best one next to the ars sensor as detailed.