Team:PKU Beijing/Project/Output

Design

The OR gate and output module is constructed as below: Salicylate promter is placed upstream of the PO promoter, the double promoter construct can act as an OR Gate, either PhiR73 or salicylate can activate the promoter.

fig1. OR Gate and Output

In [http://parts.mit.edu/igem07/index.php/Cambridge/Amplifier_project Cambridge 2007 Amplifier project], the PhiR73 activator and the PO promoter is used to amplify signal from an inducible promoter.

fig2. Cambridge 2007 amplifier project
picture from [http://parts.mit.edu/igem07/index.php/Cambridge/Amplifier_project Cambridge 2007 page]

In order to make the transcription level from PO promoter similar to that of the sal promoter, the activator is designed to be on a lower copy plasmid than the reporter. This is also discussed in the second stage assembly section.

Testing

In order to test whether the OR Gate works, we constructed the following 2 strains of E.coli to test each of the two promoters.

The first strain is to test the PO promoter, which consists of an PhiR73 activator that can be induced by salicylate. The Second strain is to test the Salicylate promoter(after PO promoter is inserted in between the pSal and the Transcriptional Unit).

Fig4. OR Gate activated by Salicylate. In order to see whether the inserted PO has blocked the function of the salicylate inducible promoter, we use salicylate to induce the strain. Fluorescence is observed, which demonstrates that salicylate promoter works in the OR Gate.

The result of the induction is shown right: Fig3 shows the result of the first strain induced by salicylate. Fig4 shows that of second strain, induced by salicylate.

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