Cell Counting Kit-8 (CCK-8) assay of cytotoxicity and synergistic cytotoxicity

AML cells (2×10⁴) and AML blast cells (2×10⁵) were seeded in a 96-well tissue culture plates and exposed to different drug concentrations for 45 or 44 h at 37°C in a 5% CO₂ atmosphere incubator. A total of 10 µl CCK-8 solution (cat. no. CK04; Dojindo Molecular Technologies, Inc.) was added to each well, followed by incubation for an additional 3 or 4 h. Subsequently, the absorbance was read at 450 nm using a Multiskan Mk3 microplate reader (16).