Figure 2. Heatmap depicting the Z-score of the log base ten in serum metabolites concentration (rows) between individual (columns) wild type and Gulo−/− mice treated with different amounts of ascorbate. Columns are reordered by hierarchical clustering using the genotype and ascorbate treatments to label the three leaves. Metabolites are grouped according to chemical classification. Wild type animals are labeled WT.1 to WT.6. Gulo−/− mice treated with 0.4% ascorbate in drinking water are labeled GV.1 to GV.6. Gulo−/− mice treated with 0.01% ascorbate are labeled G.1 to G.6. Gulo−/− mice treated with 0% ascorbate in drinking water from the age of three to four months are labeled GNV.1 to GNV.6. The Euclidean distance and complete agglomerative methods were used for clustering.