Many European Arabidopsis researchers use transgenic Arabidopsis lines from NASC, which has a large catalogue of germplasm kept up-to-date by donations from plant scientists and industry from all over the world. The catalogue is searchable by keyword, collection, or ontology and there is a help page containing a number of useful tips on searching, ordering and referencing the collection. Also available are photos of each line and tips on working with Arabidopsis.
NASC run an Affymetrix Service. The current lowest all inclusive price is £250 for RNA onto any plate based chip. NASC are happy to process any private consortium chip or a chip from another species, as well as any commercially available Affymetrix Chip.
Microarray data is available from NASC free of charge, and users can donate their own microarray data. Again, there is a help page for this service containing tips on data analysis, and elsewhere there is advice for new users of microarrays including advice on sample preparation and NASC’s requirements.
You can follow NASC on Twitter on @NASCArabidopsis for updates on new array experiments and germlines.