Figure 3

Percoll density gradient centrifugation of W83 and epsC mutant. 1 ml of a OD₆₉₀ = 4 suspension of overnight-grown P. gingivalis was layered on top of a stepwise Percoll gradient (10-80%) and centrifuged at 8000 × g for one hour. The gradient is visualized using fuchsine-stained layers in the marker (M).W83 reproducibly settles in the interfaces of 10-20%, 20-30% and 30-40% where most of the bacterial material is found in the 20-30% interface. The epsC mutant settles as a distinct, granulous band at the 50-60% interface.