From 2007.igem.org

Projects

Project Design: Wet Lab

Project Design: Printer and Software

Testing

Constructing our Project: The Wetlab

Protocols

Final Result of E.co Lisa

Logic Circut

We are planning to build the simple system diagrammed above in order to eventually express agarase through laser activation of E. Coli. Since we have many of the parts in composite form, the goal will be to attach together the 5 composite parts above.

Construction Outline

As of August 2 we have put together R0084 with A340620, as well as S01414 with I13504. On August 6 the plates of the parts need to be put into overnight liquid cultures, so that they can be plasmid-prepped on the 7th. Once we have the plasmids, we can put them together using the construction technique. After construction, this product will be transformed into both TOP10 and CP919 E. Coli using the transformation technique, and grown overnight. On the 8th we should have the finished simple system (except for the M part which is under construction still). It can be verified by adding AHL to the plates. After a few minutes, the cells (if they’re TOP10) should be glowing brightly green, while the cells in CP919 should not be.

When designing this system, there were some possible problems noted with a pivotal part in our system, OmpF (R0084), the promoter controlled by the light-sensing system.

There were some contradictions in the literature about what this part did, and exactly how it would respond to light. Also, this is not the part that the Texas team used in their project; they used the opposite part OmpC. We have decided to go ahead and begin testing OmpC, and to begin putting it together with other parts, just in case we need to use it. The part will first be put onto a test construct, I13504 AC, so that the functioning and reliability of the promoter can be tested in both TOP10 and CP919 (the knockout strain needed for functionality of the light sensing system). If the part proves viable, it will be attached to an inverter and then construction will begin using it.

Parts R0082 and R0083 need to be attached to I13504 AC, so they must first be taken from plates and grown overnight in a liquid culture on the 6th. On the 7th, the plasmids can be prepped out and each of the R parts may be attached to I3504 AC using the construction technique on August 7th. At the same time, the two promoters should be attached on to part A340620 AC, and these plasmids stored for possible future use.

After both of these new parts have been made, they need to be transformed into both CP919 and TOP10. It is expected to glow in TOP10, though not brightly, while in CP919 it may glow brighter. Both of these new constructs need to be saved until the M part is ready, and can be added to the end. Once this is complete, the three different Omp promoters can be tested against each other.

RNA Lock and Keys

One of the parts we were interested in using (for our off-switch) is an RNA lock and key to control translation. The lock first needs to be tested, to see how tight its control really is. To do this, it will be attached to a GFP testing part I13401 AC, and then a constitutive promoter placed in front. Since there should be no way to unlock the RBS in front of the GFP, the cells are not expected to glow at all. At the same time the lock test is being constructed, the relevant key needs to be attached to a constitutive promoter, and then this construct attached to the locked GFP. This new construct should be transformed into bacteria, and these cells are expected to glow quite strongly. Each of these testing procedures needs to be done in parallel, as there are two sets of lock/keys to test out.

Any crosstalk between the two sets of lock/keys also must be tested for. To do this, the key construct 1 needs to be attached to lock construct 2, and as well 2 onto lock 1. There should be no expression of GFP in either of these crosstalk experiments, or at least none more then the cells containing only one lock construct.

Finally, the rate of control needs to be characterized for the RNA lock/keys. To do this, an inducible promoter needs to trigger expression of an RNA key, and for this we will be using R0062. To do this, we first need a standard control. R0062 will be attached to I13504 AC. After that, a constitutive promoter needs to be put in front of S01414 (which is necessary for functioning of the AHL promoter). This construct should not glow in TOP10, until AHL is added, and the speed of this expression should be characterized.

During construction of the lock pieces, another part should be made by putting S01414 (RBS and LuxR) behind the locked GFP, and before the terminators. This construct should not glow on its own, but should after addition of AHL.

Construction Schedule

Monday August 6th - Over night cultures made for several parts

• R0084+A340620 AC
• S01414+I13504 AC
• J01080+I13401 AC
• R0082
• R0083
• J23008
• R0040

Tuesday August 7th - plasmid preps of all of the over nights started on Monday August 6th
Attachment of...

• R0084+A340620 (as insert) and S01414+I13504 AC (as vector)
• R0082 (insert) and I13504 AC (vector) [Into TOP10 and CP919]
• R0082 (insert) and A340620 AC (vector)
• R0083 (insert) and I13504 AC (vector) [Into TOP10 and CP919]
• R0083 (insert) and A340620 AC (vector)
• R0040 (insert) and J01080+I13401 AC (vector)
• J23008 (insert) and B0015 (vector)
• S01414 (insert) and B0015 (vector)

At this point several parts still need to be transfomred...

• J01010
• J01008
• E0040

Wednesday August 8th - Overnights of the transformed and constructed parts from yesterday.
Digest with Not1 and then run on a gel to verify the lengths of the plasmid preps done yesterday

Thursday August 9th - Plasmid preps of all of the overnights.
Attachment of...

• R0040 (insert) and J01010+I13401 AC
• R0040 (insert) and J23008+B0015 (vector)
• J01008 (insert) and B0015 (vector)
• J01010 (insert) and I13401 AC (vector)

Also a plasmid switch for E0040 into a K vector

Friday August 10th - No1 digest and gel verification of all of the plasmid preps done on the 9th