4.6. Cell Viability Assay

Cells were seeded in quadruplicate in 96-well plates overnight and the culture medium was removed. Wells were replenished with new medium containing experimental samples for 24 h, and then cell viability was determined using the MTT assay. Briefly, the culture medium was removed and the cells were washed with phosphate buffered saline (PBS). Then, MTT (Sigma, St. Louis, MO, USA) dissolved in DMEM was added to each well to attain a final concentration of 0.5 mg/mL. After 1 h of incubation at 37 °C, the media were removed and 0.1 mL DMSO was added and incubated for 15 min to solubilize the MTT. Optical density was measured at 570 nm with an iMark microplate reader (Bio-Rad, Hercules, CA, USA). Cell viability was expressed as a percentage of control cells.