Confocal microscopy analysis of the interaction between activated neutrophils and human monocyte-derived OCs. (A) LPS-activated human neutrophils prelabeled with PKH67 green fluorescent linker were incubated for 1 hour at 37°C with mature OCs previously labeled with CellTracker Orange CMTMR. Cells were washed vigorously to eliminate nonadherent neutrophils and visualized by live-confocal microscopy using Olympus Fluoview microscope (magnification, ×1500). (B) Details of cell-cell contact between activated neutrophils and OCs: (i) stacking view; (ii) z plan of y-axis; (iii) z plan of x-axis.