Cell replication assay.

Cells were cultivated for 12 h, 24 h, 48 h and 72 h in 96-well plate before adding 100 µl MTT (5 mg/ml) per well. Absorbance value for each well was collected at 570 nm using Multiskan FC Microplate Photometer. Y-axis denotes relative absorbance value at 570 nm while the absorbance value at 12 h was set as 1.