Figure 5

Mainstream CS exposure of cells. The viability based on resazurin assays of (a) BEAS-2B and (b) A549 cells following different post-exposure periods (4, 24, and 48 h). For each post-exposure time point, a different set of three inserts was used. For each treatment group (n =6, two smoke runs and three replicates), comparisons were performed with a mixed design ANOVA model using the exposure run as the error term. The raw p-values are denoted as "*" and "**" when below 0.05 and 0.01, respectively. RFU: Relative fluorescence units. Triton: Triton X-100 at 1% final concentration was used as a positive control. Incubator control ALI: non-exposed incubator controls of inserts growing at the ALI, Submerged: non-exposed cells seeded on inserts, however kept in submerged conditions. The percentages of CS used are indicated below the bar graph.