From 2007.igem.org

Figure 1: Following two figures are selected from five parallel experiments aiming at verifying the function of immobilized amplified cells. The function curves of generator cells and block cells are also displayed in the same figure to emphasize the effects of amplified cells. Actually, the curves of amplified cell( marked as 8P) is identical with that of generator cells, a phenomenan which could be attribute to self-activation of amplified cells because of its leakage expression of AHL. Since the threshold of Quorum Sensing is far below than our expectation, further adjustment need to make to eliminate the leakage expression of AHL to a reasonal level to avoid such a condition.




Figure 2: One of our strategy is to cut down the functional part from original plasmid and transfer into a plasmid with a copy number less than 10 without the addition of IPTG (pSB2K3). With the addition of IPTG,the copy number of this plasmid could rise to as much as more than 100, so enhancement of the amplification could be achieved. Although the result is not ideal as that of other types of cells, the graph equally shows AHL signal could be slightly magnified after the addition of IPTG and AHL. The background expression of AHL still stays at a high level which makes the curve of control identical to those added with IPTG and AHL. However, compareing the sapphirine curve with the blue curve, we can see after two hours, the AHL signal is remarkablly magnified after the addition of IPTG and AHL. The right graph substantiate our hypothesis either where the green and blue curve represent the cells with and without induction of IPTG respectively.