RPS detailed method and result

1. Previous lasI promoter activity

1.1. Sample

PlasI(BBa_J64010)-rbs-gfp-TT on pSB3K3 / Ptrc-rbs-lasR-TT on pBR
promoterless-gfp on pSB3K3 / Ptrc-rbs-lasR-TT-PlasI-rbs-cI-TT on pBR (negative control)

1.2. Method

①Overnight culture of sample strain grown at 37 °C in LB medium containing carbenicillin and kanamycin, and overnight culture of promoterless negative control grown at 37 °C in LB medium containing carbenicillin and kanamycin were diluted 1:300 in the medium, and then they were incubated at 37 °C as fresh cultures.
②After their OD600 reached 0.2, we added 3 µL of 500 µM 3O-C12-HSL (3OC12-HSL+) or 3µL of DMSO (3OC12-HSL-) into the fresh cultures.
③After 3-hour incubation at 37 °C (OD approximately reached 1.50.), 0.25 mL of each culture was harvested by centrifugalization and suspended by adding 1 mL of PBS (phosphate-buffered saline).
④We 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.

1.3. Result