Figure 3: This figure displays YFP and PpIX fluorescence and ANOVA main effects for various points during a time course. Absolute fluorescence of PpIX (a) displays an increase in fluorescence over time, suggesting that cells may need more time to metabolize 5-ALA and accumulate PpIX. YFP fluorescence (b) was also increased over time, being indicative of cell growth over time. The bottom figure (c) represents relative PpIX accumulation (PpIX/YFP). The ratio demonstrates that PpIX is dependent upon the number of cells available to metabolize the 5-ALA and shows the importance of quantifying PpIX fluorescence.