A device to detect the copper ion.
The device contains a promoter,a riboJ,a RBS,a repoter and a terminator. The promoter copA is a inducible promoter which is induced by copper ion, and the riboJ will stabilize the function of other parts. The GFP can be used as a repoter and the composite can report the copper ion more accurate than the single copA. Based on the analysis of the GFP induced by Cu2+, all of the copa which are induced by different thickness of the Cu2+ showed a trend of twice induction.
Figure.1.Changes in fluorescence induced by different thickness of copper ion in E.coli BL21. Figure.2.Changes in fluorescence induced by different thickness of copper ion in E.coli DH5α. Figure.3.Changes in fluorescence in E.coli without induction. Figure.4.Changes in fluorescence in E.coli which do not contain copA and fluorescent protein.
The figures above show that at about the 2th hour, the increasing of GFP appeared firstly, at about the 5th hour the second induction appeared, and all of the induction can only last for 1 hour .It seems that the promoter copa need the certain concentration of Cu2+ to start and the certain concentration of Cu2+ could also induce the E.coli to discharge the Cu2+ which could close the induction of the copa.The concentration to induce the copA is lower than that can induce the device for discharging copper ion. Also, we can obviously find that the protein degradation is much faster in DH5α than that in BL21 through the figure.1 and figure.2 for the BL21 has a deficiency of protease. In the group of 0μmol/L Cu2+, the fluorescence shows a trend of falling firstly then rising.Actually , the fluorescence which produced by the leakage of copA will not change. The change quantity comes from the different growth periods of the E.coli.We remove some of the bacterial fluid into new medium for the thickness is large enough for flow cytometry.So the bacteria will go through a period of growing from growth period to maturation period, so as to the change of the fluorescence.
Sequence and Features
- 10COMPATIBLE WITH RFC
- 12COMPATIBLE WITH RFC
- 21COMPATIBLE WITH RFC
- 23COMPATIBLE WITH RFC
- 25COMPATIBLE WITH RFC
- 1000INCOMPATIBLE WITH RFCIllegal BsaI.rc site found at 976