Assessing MCF-7 Cell Viability in 3D

To assess cell viability in low attachment conditions, 250,000 MCF-7 cells were seeded in 6-well low attachment plates (Corning, NY, USA). Forty-eight hours later, cell viability was assessed using trypan-blue staining. Non-viable cells were excluded and living cells were quantified using an automatic counter (Countless II, ThermoFisher, Waltham, MA, USA). Cells were reseeded in 96 well plates and cell viability was assessed 72 hours later using the CellTiter-Blue Assay (Promega), as described^{41 (link)}. Absorbance was detected (560 nm excitation and 590 nm emission) using a Victor X4 Multimode Plate Reader (PerkinElmer, Hopkinton, MA, USA). Experiments were performed in triplicates in at least 3 independent experiments.