Figure 1. Membrane integrity evaluation using the neutral red test on Chang (WKD) and IOBA-NHC cells. This figure shows the membrane integrity evaluation using the neutral red test (microplate cytofluorometry) on Chang (WKD) and IOBA-NHC cells after two incubation times, 15 min of treatment with different BAC concentrations (WKD 15 min, IOBA-NHC 15 min) and 15 min of treatment with different BAC concentrations followed by 24 h of cell recovery in complete medium (WKD 24 h, IOBA-NHC 24 h). Note that membrane integrity decreased in a concentration-dependent manner on both cell lines. The asterisk denotes statistically significant differences between the two cell lines after 15 min of treatment (p<0.01), and the sharps (hash marks) denote statistically significant differences between the two cell lines after 24 h of cell recovery (### p<0.001, ## p<0.01, # p<0.05). BAC, benzalkonium chloride; PBS, phosphate buffered saline. Means±SEM.