Part:BBa_K649001:Experience

Applications of BBa_K649001

Fluorescence intensity of BBa_K649001 was increased by 3OC12-HSL induction. GFP expression after induction of 3OC12-HSL is 170 times as high as before.

Effect of 3OC12-HSL induction on fluorescence intensity
This work is done by Takuya Tsubaki.

Generally, in the presence of 3OC12-HSL, LasR activates lasI promoter and the transcription level of downstream gene increases, but in the absence of 3OC12-HSL, LasR can't activate lasI promoter. To characterize BBa_K649000, we used Ptrc-rbs-lasR-TT as regulator part. Because LasR is constitutively expressed, the difference of fluorescence intensity by 3OC12-HSL induction indicates that BBa_K649000 is successfully regulated by 3OC12-HSL.

[Sample]

Ptrc-rbs-lasR-TT / PlasI(BBa_I649000)-rbs-gfp-TT

Ptrc-rbs-lasR-TT / Promoterless-rbs-gfp-TT (negative control)

[Method]

1. Overnight cultures of sample strain grown at 37 °C in LB medium containing carbenicillin and kanamycin were diluted 1:100 in the medium, and overnight cultures of promoterless negative control strain grown at 37 °C in LB medium containing carbenicillin and kanamycin were diluted 1:200 in the medium , and then they were incubated at 37 °C as fresh cultures.
2. After their OD600 reached 0.2, we added 3 µL of 500 µM 3OC12-HSL (3OC12-HSL+) or 3 µL of DMSO (3OC12-HSL-) into the fresh cultures.
3. After 3-hour incubation at 37 °C (OD reached approximately 1.80.), 0.25 mL of each culture was harvested by centrifugalization and suspended by adding 1 mL of PBS (phosphate-buffered saline).
4. We dispensed 500 µL of each suspension into a disposable tube through a cell strainer, and its fluorescence intensity was measured with a flow cytometer of Becton, Dickinson and Company.

We improved previous las promoters.

1. our assay of BBa_J64010
2. BBa_K091117
3. BBa_R0079
4. BBa_K195616
5. BBa_J69551

To prove that the LasR regulator used in our lasI prmoter assay works, we did another assay. Details about this assay can be found [http://2011.igem.org/Team:Tokyo_Tech/Projects/RPS-game/assay#1. here].

User Reviews

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No review score entered. 2013SUSTC-Shenzhen-A

2013SUSTC-Shenzhen-A[http://2013.igem.org/Team:SUSTC-Shenzhen-A] tested the BBa_K649001, and it works. Data we get:

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