4.9. Cell Glo Viability Assay CellTiter-Glo® Assay

The CellTiter-Glo Luminescent Cell Viability Assay (Promega; San Luis Obispo, CA, USA) was used to determine the number of viable cells based on quantitation of the ATP present which signals the presence of metabolically active cells [45,46]. Cells (5000/well) in 100 µL of culture medium were seeded in 96-well opaque-walled plate. Control wells containing medium without cells were included to obtain a value for background luminescence. Then, test compounds (dacarbazine and cisplatin) were added to experimental wells and incubated for 24 h following published standard procedures [24]. After incubation, the plate was equilibrated at room temperature for approximately 30 min and 100 µL of CellTiter-Glo Reagent was added to each well containing 100 µL of medium containing cells and mixed for 2 min on an orbital shaker to induce cell lysis. Then, plate was incubated at room temperature for additional 10 min to stabilize luminescent signal and luminescence was measured using BioTek Synergy 2 Reader (BioTek, Winooski, VT, USA).