Cell viability is quantified in Figure 5 and corresponds with the fluorescent intensity data obtained above. Here, different concentrations of metformin (400 µM, 800 µM, 1.2 mM, 1.6 mM, and 2.0 mM) were added to A549 cells either in the presence of 250 µM sulindac or not. When no metformin, 400 µM metformin, 800 µM metformin, and 1.2 mM metformin are combined with 250 µM sulindac, absorbance values remained in the range of ~0.5 to ~0.7 nm. However, once 250 µM of sulindac was added to 1.6 mM of metformin, absorbance dropped from ~0.6 nm to less than 0.4 nm. This indicated the potency of the combination of 250 µM and 1.6 mM metformin, as a drastic reduction in cell viability, which corresponds to measured absorbance, was observed. 2.0 mM metformin and 250 µM sulindac demonstrated analogous outcomes. However, it is advisable to avoid using a drug combination with concentrations that are higher than necessary. The combination of 1.6 mM metformin and 250 µM sulindac was also used in time-lapse fluorescence imaging, indicating that fluorescence information can be used to validate cell viability data.