DNA migration values were expressed as tail intensity values (percentage of whole comet intensity) according to the formula: Sum of all intensity values less the intensity values from the mirrored head region. Migration values were determined in a minimum of 50 randomly selected cells per slide. Tail intensity values of each WS-exposed group were compared to the SA group using one-way analysis of variance (ANOVA) followed by Dunnett’s multiple comparison test. The mean of 3 slides from each group was compared to the SA control for each cell line and each assay. A value of P < 0.05 was considered

to be statistically PARP inhibitor significant for comparison between data sets. In both cell lines, the majority of the cultures exposed to WS showed viability above 75% (Fig. 3 and Fig. 4), mainly for the highest dose groups. At the highest WS concentration (0.2 l/min dilution velocity), viability ranged from 40% to 70% for A549 cells and from 55.7% to 90% for BEAS-2B cells, with 5 out of 5 assay replicates below 75% viability for the A549 cell line and 4 out of 5 for the BEAS-2B cell line. At lower smoke concentrations, viability for the A549 cell line was below 75% for 1 out of 5 assay replicates at 1.5 l/min dilution velocity and 2 out of 5 at 1.0 l/min and 0.5 l/min AZD1208 solubility dmso dilution velocity, with viability values ranging

from 48% to 74% for the A549 cell line and 1 out of 5 assays at 4.0 l/min and 3 out of 5 assays at 1.5 l/min dilution velocity, with viability values ranging from 47.5% to 73%. For Astemizole all experiments and both cell lines, a clear dose-dependent increase in DNA damage was seen, demonstrating the genotoxic potential of WS. In A549 cells, the comparison between the control and all WS dilutions showed statistically significant differences with regard to DNA damage, expressed as tail intensity (P < 0.001). The increases in response to WS over the

control varied from 5.2-fold to 17.3-fold, indicating a clear dose–response for all assays ( Fig. 3. For the BEAS-2B cell line, the increase of DNA damage in treated cells was also statistically significant when compared to control (P < 0.001). The manifold increases in damage in response to WS over the SA control were up to 3.9-fold, demonstrating a clear genotoxic effect. Exceptions were found for 2 of 3 experiments (same-day assay) of the highest dilution (4 l/min), where no statistically significant difference was seen ( Fig. 4A). Repeatability and reproducibility were evaluated by determining the relative standard deviation (RSD) between each assay performance for each cell line. For the A549 cell line, RSD values ranged from 4.61% to 37.44% for repeatability and from 5.90% to 39.78% for reproducibility (Table 2). For the BEAS-2B cell line, RSD values ranged from 6.36% to 16.83% for repeatability and from 9.73% to 22.66% for reproducibility (Table 3).