Skip to main content
. Author manuscript; available in PMC: 2014 May 13.
Published in final edited form as: Biomacromolecules. 2013 Apr 17;14(5):1474–1481. doi: 10.1021/bm400149a

Figure 3.

Figure 3

Schematic of assay used to calculate the average extracellular concentration, cPIA,Biofilm, of PIA. a) A schematic of the protocol to calculate total number of PIA molecules per biofilm cell (nPIA). b) An x-y CLSM image of bacterial cells (green) within the biofilm. c) A 3-D reconstruction of a biofilm volume using centroid data obtained using image analysis 31. The number of cells within that volume was taken as local cell number density (ncell cells/μm3). c) The reciprocal of the cell number density, Vtotal = 1/ncell, is shown. The volume, VPIA, available to PIA molecules per biofilm bacteria (nPIA) was calculated as Vtotal − Vbacteria (Table 1). The extracellular PIA concentration within the biofilm, cPIA,Biofilm, was then calculated as nPIA/VPIA.