Unstained and stained cells cytograms.

Cytograms of forward-scatter (FSC-H) vs. green fluorescence (530/30 nm) showing populations of Cladocopium sp. CCMR0093 cells in culture after 4 h of exposure to 28°C. (a) Live symbiont cells in cultures with no addition of ROS-reactive fluorochrome H2DCFDA and (b) with 10 μM of the fluorochrome. The horizontal red line represents the green fluorescence threshold for non-stained cells and is set to the same level in both cytograms for comparison. In this example, a background of 2.6% of cells were observed above threshold in the non-stained culture whereas 23.9% of the cells displayed fluorescence above threshold in the H2DCFDA treated culture. Forward scatter and fluorescence values are in log scales. a.u.: arbitrary units. (JPG)