Figure 1. Biomass distribution in plaque biofilms. (a) Mean biomass volume throughout the depth of plaque biofilms (n = 48, error bars show ± SEM). (b) Toluidine-blue-stained sections from a typical plaque biofilm. Sections i–vi taken at distances (from enamel surface) of approximately 820 µm, 730 µm, 560 µm, 390 µm, 220 µm, and 110 µm, respectively.