Purvalanol A (NG-60) is an effective and cell-permeable CDK inhibitor with IC50 of 70/4/35/850 nM for cdk2-cyclin A/B/E, and cdk4-cyclin D1, respectively.

CDK2-CyclinE:35 nM, CDC2-cyclinB:4 nM, CDK2-CyclinA:70 nM, CDK4-CyclinD1:850 nM, ERK1:9000 nM, CDK5-p35:75 nM

Cells are seeded at 10000 density in 96-well plates and treated with various concentrations of Purvalanol A (0-100 μM) for 24 h. Cells are exposed to 10 μL of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltet- razolium bromide dye (5 mg/mL) and are incubated at 37℃ for 4 h. In order to solubilize the formazan crystals 100 μL DMSO is added. Absorbance is determined at 570 nm spectrophotometrically.(Only for Reference)

DMSO: 250 mg/mL (642.86 mM), Sonication is recommended.

Ethanol: 19.5 mg/mL (50.14 mM), Sonication is recommended.