Phosphatidylserine exposure induced by rhodium (II) citrate (Rh
) in breast carcinoma cells (lines 4T1 and MCF-7) after 48 hours of treatment. Cells were stained with annexin V-FITC (fluorescein-5-isothiocyanate) and PI (propidium iodide) and analyzed by flow cytometry. The percentage of annexin positive cells represents the cells with exposed phosphatidylserine. Data were normalized with the control (cells without treatment) and expressed as percentage of the mean ± SE of three experiments that were independently performed in triplicate. One or two asterisks (* and **) indicate statistical differences between control and cells treated in MCF-7 and 4T1 cell lines, respectively (p < 0.001).