From 2007.igem.org

AHL assay Standard protocol

prepare overnight culture (3 tubes for luxR, 2 tubes for each controls)
take 30 ul of the overnight culture into LB + Kan (⇒fresh culture)
incubate the fresh culture until the observed OD reaches around 0.80.
prepare and add AHL mixture; final concentration of AHL = 6 pM
incubation for 2 hours
1st FLA measurement for GFP expression
2nd FLA measurement for GFP expression
add the same amout AHL as the first addition