PRIMe (http://prime.psc.riken.jp/), the Platform for RIKEN Metabolomics, is a Web site that has been designed and implemented to support research and analysis workflows ranging from metabolome to transcriptome analysis. The site provides access to a growing collection of standardized measurements of metabolites obtained by using NMR, GC-MS, LC-MS, and CE-MS, and metabolomics tools that support related analyses (SpinAssign for the identification of metabolites by means of NMR, KNApSAcK for searches within metabolite databases). In addition, the transcriptomics tools provide Correlated Gene Search, and Cluster Cutting for the analysis of mRNA expression. Use of the tools and database can contribute to the analysis of biological events at the levels of metabolites and gene expression, and we describe one example of such an analysis for Arabidopsis thaliana using the batch-learning self-organizing map (BL-SOM), which is provided via the Web site.