Fig. 2From: Comparison of microbial taxonomic and functional shift pattern along contamination gradientHierarchical cluster analysis of GeoChip hybridization data of 12 samples (a) and hierarchical cluster analysis of seven genes involved in heavy metal resistance (b). Relative intensities of genes were standardized before hierarchical clustering. Significant differences (P < 0.05) among three groups are indicated by alphabetic lettersBack to article page