FIGURE 5: Bland-Altman plots and correlation analyses between the methods of cells/mL, CFU/mL, vPCR, and metabolic activity (XTT assay) for biofilms. Bland-Altmand plots between cells/mL and CFU/mL (A), vPCR and cells/mL (B), vPCR and CFU/mL (C), XTT and cells/mL (D), XTT and CFU/mL (E), and XTT and vPCR (F) demonstrated lack of agreement, since dots are not evenly distributed around the mean line (black horizontal dotted line); red horizontal dotted lines: limits of agreement (standard deviation, SD), red whiskers: 95% CI of the limits of agreement; black continuos line: regression line showing the proportional bias with the differences between cells/mL and CFU/mL tend to zero as their averages (and values) increase in (A), while the differences between cells/mL and nuclei and also between CFU/mL and nuclei augment (in modulus) as their averages (and values) increase and this trend is more pronounced between cells/mL and nuclei. Correlations between cells/mL and CFU/mL (G), vPCR and cells/mL (H), vPCR and CFU/mL (I), XTT and cells/mL (J), XTT and CFU/mL (K), and XTT and vPCR (L). The coeficient of determination (R²) shows that 62%, 69%, but only 23% of variation in cells/mL is explained by CFU/mL, vPCR, and XTT, respectively, 65% and 42% of variation in CFU/mL is explained by vPCR and XTT, respectively, and 55% of variation in vPCR is explained by XTT. Data were log10-transformed (except for XTT) for (A), (B), (C), (G), (H), (I), (J), (K), and (L) and data were normalized for their maximum value for the concordance analysis of XTT (D, E, and F).