Figure 6
CO 2 deprivation does not cause changes in cytoplasmic or periplasmic pH until 24 h. Hp 26695 was inoculated into liquid medium containing the pH-sensitive fluorescent dye BCECF free acid or BCECF-AM, and cultured under 20% O2 tension in the absence (blue line) or presence (red line) of 10% CO2. An aliquot of each culture was taken at the indicated time points and analyzed by flow cytometry. Unstained Hp cells are shown for comparison (black line). Increase in fluorescence intensity represents higher pH. Data shown are representative of two independent experiments.