Figure 4. Cytotoxicity assay on Müller cell. A: The percentage of trypan blue positive cells (y-axis) was plotted against the concentration of the test compounds used (x-axis). The concentration unit was micro molar and the open box represented a 95% confidence limit. 5-FU at 100 µM that was the highest concentration tested, caused 20% death of the cell culture, which was equivalent to HDP-PMEG at 11 µM or DNR at 0.1 µM. B: Exemplary images from the Müller cell cytotoxicity study: the upper left panel showing a counting field from the control in which 31 cells were stained by trypan blue out of a total of 435 cells, yielding a 7% trypan blue positive rate. The rest of the three fields had a trypan blue positive rate of 19% (38/198) for 10 µM HDP-PMEG, 18% (46/251) for 100 µM 5-FU, and 18% (49/274) for 0.1 µM daunorubicin (DNR).