Difference between revisions of "Part:BBa K3332082"

Revision as of 20:20, 27 October 2020

pBAD/araC promoter-RBS-EYFP-terminator

It can express cyan fluorescent protein under certain conditions.It is used to characterize the function of the mazF and inverter as a control group

Usage and Biology

This composite part is used as a control group to demonstrate the effect of inverter, comparing with proBAD/araC_inverter_EYFP_terminator (BBa_K3332079). EYFP serves as a reporter gene. By comparing the fluorescence intensity/OD600 of induced and non-induced bacteria, we can characterize the function of the inverter.

Characterization

When we were building this circuit, we did the nucleic acid gel electrophoresis experiment to verify the ligation. After the circuit was built, we sent the plasmid to sequence, and got the correct result. After new molecular cloning experiments, we did Enzyme-Cut identification for further confirmation. We used the Spe I and Pst I to cut the plasmid, then we got the target separate fragment.

Fig.2 proBAD/araC_B0034_E0030_B0015_pSB1C3 (BBa_K3332082) digested by Spe I and Pst I (about 4148 bp)

Protocol:

1. Preparation of stock solution

Dissolve arabinose in ddH2O to make 100× stock solution（the work concentration is 0.2%）

2.Culture glycerol bacteria containing the corresponding plasmid in test tube for 12h.

3.Add 4mL of the above bacterial solution into 200 mL LB medium and maintain the culture condition at 37 ℃ and 180 rpm.

4.Add 2 mL arabinose stock solution into the induction group when OD600 increased to 0.6.

5.Induce for 6 hours and the condition is the same as before.

6.Then, sampling culture in 96-well plate reader to measure the fluorescence intensity (EYFP) and corresponding OD600, then calculate the fluorescence / OD value of each group.

Here is the result:

We found that the downstream gene of proBAD/araC can be expressed when induced by arabinose, while the expression of EYFP decreases without the inducer. Besides, as we can see, the purple bar is higher on the right side (when the arabinose is absent). Therefore, we can come to the conclusion that when the inverter is added, the effect is reversed.

Sequence and Features