Quantification of agfB expression in strain ATCC 14028 cultures fractionated with fibronectin-coated magnetic beads. The ATCC 14028 agfB::lux reporter strain was grown in 1/10 LBns-Dp for 48 to 120 h at 28°C without agitation prior to fractionation with fibronectin-coated magnetic beads (FN-beads). Expression (cps) from cells in unfractionated culture, FN-bead, and supernatant fractions was normalized to the amount of DNA in each sample and is represented as relative light units (RLU). Bars represent the average RLU values ± standard deviations (error bars) from five independent samples measured in triplicate. Statistically significant differences between FN-beads, supernatant, and culture samples are noted by asterisks (**, P < 0.01; *, P < 0.05) as determined by two-way analysis of variance.