3D-reconstructions of a 146 x 146 μm section of biofilms grown for 64.5 h in iHS medium. FISH staining of a fixed biofilm. P. gingivalis and T. forsythia are shown schematically as dots (fluorescence maxima of the cells). (A) cyan: T. forsythia, red: P. intermedia, green: non-hybridised cells, DNA staining (YoPro-1 + Sytox). (B) cyan: T. denticola, red: P. gingivalis, green: non-hybridised cells, DNA staining (YoPro-1 + Sytox). Figures show a representative area of one disc.