FIG. 2.

Induction of apoptosis in RAW 264.7 cells by H. pylori as assessed by fluorescence microscopy using acridine orange and ethidium bromide staining. (A) Untreated RAW 264.7 cells show normal cellular morphology and display intact nuclear architecture, as demonstrated by the green fluorescence of their nuclei (magnification, ×250). (B) RAW 264.7 cells treated with staurosporine for 24 h (positive control for apoptosis) show morphological features characteristic of apoptosis, as demonstrated by the enhanced fluorescence of their condensed chromatin. Early apoptotic cells fluoresce green (arrows), and late apoptotic cells fluoresce orange (arrowheads) (magnification, ×250). (C) H. pylori-infected cells (MOI, 50:1; 24 h) show features of apoptosis similar to those of staurosporine-treated cells (magnification, ×400).