Figure 4.

Atomic force microscopy examination of biofilm. (A) A piece of plaque biofilm coembedded with tissue was located in a hematoxylin and eosin (H&E)–stained section (between 2 arrows in top panel). CT, connective tissue. Area corresponding to the white-boxed region in the H&E-stained section was examined in the serial section stained with alcian blue under high magnification (×1,000, bottom panel). Two typical areas were chosen based on alcian blue staining and examined by atomic force microscopy: (B) blue- and (C) red-boxed areas from panel A. Areas a–c (D–F, respectively) from Figure 3A were examined by atomic force microscopy. Thick arrows indicate biofilm-like structures within tissue. Thin arrows indicate scattered bacterial cells. C, eukaryotic cell.