FIG. 5.
Impact of cell density on hmuY, hmuR, tlr, fetB, and pg1237 expression. P. gingivalis 33277 cells were grown to early log phase and resuspended in 4× diluted TSB media to reach a final cell density of 5 × 108 (1×) or 5 × 109 (10×) per ml, respectively. Expression of iron-related genes in 33277 in response to different cell densities was determined by using real-time RT-PCR. The change in expression levels was calculated by the ΔΔCT method, where ΔΔCT = CT(1× cell density) − CT(10× cell density) and ratio = 2−ΔΔCT. The expression of pg1737, tlr, and fetB was used as a control.