Annexin-V and PI doubling staining of virus-inoculated splenocytes. (A) JS3/05. (B) JS5/05. (C) F48E8. (D) Herts/33. (E) Control. Green: early apoptotic cells with PS exposure upon the outer leaflet of the cell membrane (Annexin-V +); Green and red: late necrotic cells with PS exposure and the ruptured membrane (Annexin-V/PI +); Red: released cellular DNA from leaky necrotic cells (PI +). Magnification, × 400.