Figure 2. LDR induced cell senescence but not apoptosis. (A and B) MTT assay for analyzing the cell viability of LDR treated WI-38 cells and H1299 cells, respectively. (C and D) Western blot analysis of Caspase-3 and Caspase-9 for detecting the cleaved proteins in LDR treated WI-38 cells and H1299 cells, respectively. (E) SA-β-gal analysis for determining the level of cell senescence induced by LDR. (F) Quantification of X-gal stained cells before and after LDR. *p < 0.05.