FIGURE 4.

Two-way clustering of differentially expressed E. coli genes. Ward’s Hierarchical Clustering was performed to analyze propensity transformation (PT) values (A) and RPKM values (B) of E. coli genes in response to 1 μg, 5 μg, and 10 μg of ClO₂ treatments after 1 h, 2 h, and 3 h. The number of clusters was set at 20 shown in Additional file 2: Supplementary Table S2, and clusters were color coded. Red indicates high expression and green (A)/blue (B) indicate low expression.