Fig. 4From: The antimicrobial effects and mechanism of ε-poly-lysine against Staphylococcus aureusPCA scores plot for control group and ε-PL-treated group. a Sampling time: 2 h; b sampling time: 4 h. In the scores plot, the confidence interval was defined by the Hotelling’s T2 ellipse (95% confidence interval), and observations outside the confidence ellipse were considered outliersBack to article page