2.13. Statistical analysis

Prism 8.4.3 software was used for statistical analysis. The normality of all datasets was assessed with the Shapiro-Wilk test. Normally distributed data were compared using the Student’s t-test for paired or unpaired samples, depending on experimental design. Non-normal data were compared with Mann-Whitney’s or Wilcoxon’s rank match-paired tests. Comparisons of more than two groups used Kruskal Wallis multiple analyses followed by Dunn’s post test. Spearman’s test was used to assess parameter correlations. Sigmoidal dose-response curves were transformed into a linear form using natural log transformation for dilutions and the function NORM.S.INV (Microsoft Excel) function for normalized OD_450 nm data according to:

NORM.S.INV[(OD450nmSample-OD450nmMinimum)/(OD450nmMaximum-OD450nmMinimum)].

Paired comparison of slopes and X and Y intercepts, after adjusting data to a linear equation, indicated no significant differences between the results for each coating condition. Experimental designs included two replicates per sample and three independent experiments.