Figure 1 of Burke, Mol Vis 2011; 17:2864-2877.

Figure 1. Dose-dependent H2O2-induced toxicity in ARPE-19 cell populations shown by dynamic changes in propidium iodide (PI) fluorescence. PI fluorescence (in arbitrary units) was measured over 20 h in replicate wells of ARPE-19 cultures exposed to varying amounts of H2O2. A: H2O2 delivered as pulse at the concentrations indicated. B: Isolates three components of the curves for PI fluorescence intensity that were used for comparison between treatment groups, using 600 (X's) and 700 μM (circles) H2O2 for illustration. The times of onset of the fluorescence rise (red) relative to baseline at 2 h (black), the mean slopes (green), and the peak fluorescence values (blue) were determined as described in Table 1. C: H2O2 generated enzymatically by the addition of glucose oxidase (GOx) at the mU/ml concentrations indicated. Data in A and C are the means of 3–6 replicate culture wells per group within representative experiments.