Characterization and analysis of cell viability in HMrSV5 cells. (A) Confluent PMCs were positive for cytokeratin 18 and vimentin. Scale bars: 50 μm. (B) Cell viability was determined by MTT assay. The left panel shows the viability of HMrSV5 cells exposed to different concentrations (0, 0.1, 0.5, 1.0, 2.0 and 5.0 μg/ml) of LPS for 24 hours. The right panel shows the viability of HMrSV5 cells exposed to 1 μg/ml LPS for different times (0, 3, 6, 12, 18 and 24 hours). The results are presented as a percentage of the MTT absorbance of untreated cells (100%). Data represent mean values ± SD (n ≥ 3). (C) Detection of cell viability by flow cytometric analysis. The upper panel shows dose responses for LPS-induced apoptosis over 24 hours in HMrSV5 cells. The lower panel shows apoptosis in cells treated with 1.0 μg/ml LPS for 0, 3, 6, 12, 18 and 24 hours.