Cell viability determination by cell counting kit-8 (CCK-8) analysis

Transfected or non-transfected cells (1×10⁴ cells/ml) were seeded in 96-well cell culture plates and incubated for 24 h. Then, 10 μl CCK-8 agent (03285; Merck, St. Louis, MI, USA) was added to each well followed by another 2-h incubation at 37°C. Next, the optical density (OD value) was determined at a wavelength of 450 nm in a microplate reader.