Figure 6. Comparison of cell viability after 4 and 7 days in vitro. The percent of the initial number of cells seeded that remain viable and attached was measured using the CellQuanti-Blue™ assay both in light (blue) and dark (red) culture conditions. The percent of cells that remain viable was significantly higher in experiments performed in dark-adapted conditions (the asterisk indicates a p<0.001). Error bars represent the standard error of the mean.