Figure 6

TUNEL assay to detect DNA fragmentation by confocal microscopy. Images are fluorescent confocal staining at ×600 magnification. Negative control was unchallenged HGECs at 24 h. Positive control was HGECs treated with DNase 1000 U/ml. HGECs were challenged with purified HRgpA (8 μg/ml), RgpB (5.2 μg/ml) and Kgp (3 μg/ml) (equivalent to 113 units of Rgp activity/ml or 12.4 units of Kgp activity/ml) for 2, 4, 8, 15 and 24 h.