FIG 5 .

Biochemical assays. (A) Luciferase-based quantification of extracellular ATP. No significant differences were found between biofilm and planktonic levels at 2, 4, or 8 h postinoculation in matched E. faecalis samples. Results are averages from four independent experiments. Only the values for the 4-h OG1RF samples (planktonic and biofilm) are above the instrument background; neither rose to statistical significance. (B) The cell-impermeant fluorescent dye Sytox green (Invitrogen) was used to label nucleic acids outside functional cells. eDNA levels were >10³-fold higher under biofilm conditions than in matched planktonic controls. Exogenous lysis of a small fraction of cells (~5% by microscopy) produced a luciferase signal that saturated the instrument detector under the displayed conditions (not shown). Error bars indicate 1 SD.