From 2007.igem.org

An actual demonstration is determined to show the extensibility of our method.

This demo system

• is designed as simple as possible, without any "cool" logic function;
• includes all the three logic gates, which constitute a three-level logic circuit;
• shows that wires can cross and branch off (without interference);
• is loaded on two plasmids, http://partsregistry.org/Part:BBa_I732923 pSB1A3-I732923 and http://partsregistry.org/Part:BBa_I732925 pSB3K5-I732925 ,and practically transformed into Top10 strain;

• accepts aTc and AHL signals as inputs;
• produces RFP and GFP signals as outputs;
• can be "reset" by IPTG signal (i.e. both of the outputs are lightened when IPTG added in);
• is expected to put out the results that accord with the truth value shown in Figure 2.

Logic Abstract of the Demo

We can see from this truth table that IPTG might result in both of the outputs being lightened no matter whether aTc or AHL exists or not. (It is just like the response "8888..." on the screen when you reset some of your electrical apparatus, for example, a calculator.)

Actual System

The three parts on the left are loaded on http://partsregistry.org/Part:BBa_I732923 pSB1A3-I732923, and the rest two parts are loaded on http://partsregistry.org/Part:BBa_I732925 pSB3K5-I732925. We've built up this system in one kind of TOP10 E.coli, but it seems that it cannot grow stably when concentrated aTc exists. (We have to use aTc at a high concentration for counteracting the high expression of tetR, but concentrated aTc shows some bacteriostatic activity like Tc(TetraCycline).) We may not be able to send out the very final results here exactly by Oct. 26, but we have continually been trying our best to screen out such a monoclonal strain that is not influenced by concentrated aTc. You will get the results in the coming presentation...