Fig. 3Quantification of BAI-2 fromVibrio harveyicultures using the CLPY
biosensor. (a) Wild-typeV. harveyiBAI-2 levels monitored as a function of
time and culture density. Cell-free culture filtrates were prepared by passing
the bacterial cell culture media through a 3 kDa MW cutoff filter. The filtrate
(150μl) was added to CLPY (0.015 mg/ml). The YFP/CFP FRET ratio (closed
diamonds) is plotted as a function of cell density (CFU 107 /ml;bars). The error
bars represent the standard deviations from three independent experiments.
(b) CLPY fluorescence response to culture filtrate from wild-type (BB120)V.
harveyi(closed triangles) andluxS-mutant (MM30,open triangles) culture
filtrate. The error bars represent the standard deviations from three independent
experiments (In this Figureaandb, Adapted with permission from [9]; Copy-
right©2007 American Chemical Society)84 Sathish Rajamani and Richard Sayre