Dot plot profiles of untreated and STS-treated cells.

<p>(A) Schematic dot plot diagram showing the key to quadrant division. Each quadrant represents the apportionment of cells that retain both cyt c and Smac in mitochondria or have redistributed either or both of these proteins. (B) The populations of cells for each of the staining regimes, with the specified application of antibodies (Ab), are gated in the forward scatter (FSC) and side scatter (SSC) dot plots to eliminate dead cells and cell debris, using the “No staining” population (no antibodies applied) as the basis for this R1 gate. (C) Fluorescence dot plot analysis within the R1 gate. Populations corresponding to “No staining” (autofluorescence) and “Secondary Ab only” (non-specific binding), are located in the lower left quadrant. Cells stained with both primary and secondary antibodies are overwhelmingly located in the top right quadrant (these cells were not exposed to apoptotic inducer). Quadrant delineation is described in the text. (D) Gating of cells (R3) treated with STS for 24 h; all other indications as for panel B. Note that the R2 gate in this experiment corresponds to the 6-h time point for STS treatment, data for which are not shown here. (E) Dot plot analyses for cells treated with STS for 24 h. All indications correspond to those of panel C. Red and purple colors in panels C and E, respectively, are generated by CellQuest software (i.e. neither color refers to cyt c, specifically).