Fluorescence microscopy and flow cytometric analysis of SYTO 45-stained chloroplasts. Brightfield (A) and fluorescence (B) microscopic images of chloroplasts isolated from 14-day-old seedlings after staining with 20 μM SYTO 45. The exposure time for (B) was 0.1 s. (C) Flow cytometric analysis of the same chloroplasts stained with the indicated concentrations of SYTO 45. Scale bar is 10 μm. Chloroplasts in all panels were not fixed.