Biobrick calable of forming pattern having the mathematical meaning of parabola and hyperbola

What it is

Biobrick K1412002 is the base of this part. We add promoter pTET in the front of BBa_K20600. In order to realize our goal, we also ligate pCons and TetR to control the express of BBa_K20600 with pTET.

More informtion: BBa_K1412002

What it does

Promoter pTET would be inhibited when TetR expresses, thus the lacI can’t work on the promoter pLac. Our target gene CheZ could express, which recoveries the chemotaxis of bacteria. Once anhydrotetracycline (aTc) added in the culture medium, which can restrain the express of TetR, situation would be different, lacI restrain the express of promoter pLacI, and target gene CheZ can’t express.

How to use it

To achieve our goal to form hyperbolic curve and parabola, we use anhydrotetracycline (aTc) and Isopropyl β-D-1-Thiogalactopyranosid (IPTG) as the inhibitor and inductor to regulate to whole circuit.

We use pTET as the substitution for pBAD because when cultivating the bacteria in a long time (about 24 hours) with the inhibitor L-Arabinose, the bacteria may use the L-Arabinose as carbon source. Beyond our expection, the bacteria tends to the L-Arabinose. Due to the deficiency caused by the inductor L-Arabinose, we choose aTc to abtain our goal which lead the bacteria tend to oppose direction of the location where is the aTc on the medium plate.

We use M63 semi-solid plate to observe the behavior of E.coli(CL-1). We dot proper concentration of aTc and IPTG with a distance of 1.5 cm. After the two spots dries up, we dot 3μL bacteria on the IPTG, then place the plate at 37℃. By tracking and measuring the chemotaxis diameter of the bacteria on the plate, we get a series of experimental data, more detail in Experimental Data.

Experimental Data

Sequence and Features

Assembly Compatibility: