The possibility to test for the expression of all genes simultaneously has allowed to study phenomena at a global and unprecedented level. Studies in development, phamacogenetics, physiopathology can be integrated for a whole system providing unparalleled insights into their biology. Our Affymetrix platform is equipped with one Bioanalyser, two high-resolution scanners with autoloaders and four fluidics stations. The chip platform coupled to a Bioinformatics platform that brings the crucial support necessary for data analysis. This resource, with a capacity of more than 300 chips/month, has supported numerous local projects and investigators as well as a number of Canadian and European collaborators.