Incyte has developed a new gene expression microarray (GEM) for analysis of the plant functional genomic system Arabidopsis thaliana. This GEM features over 7,000 array elements from a non-redundant cDNA collection; nearly 30% of the estimated 25,000 genes in this organism. Over 2,000 of these clones represent genes that have functional annotation in public databases. We are offering hybridization and analysis services for the Arabidopsis GEM via Incyte and Genome Systems. Arabidopsis is the primary model system for the study of dicot plant genomics. Academic and commercial groups are using the combination of genomic and genetic tools available for Arabidopsis to study complex problems in plant biology. We have performed a few biological studies using the Arabidopsis GEM to validate the platform and provide examples of possible applications. We will present sample data on these studies.