Ex situ or spotted arrays

Ex situ (also known as spotted or printed) arrays have become very popular formats, especially for the building of custom noncommercial arrays used primarily by academic laboratories [see Association of Biomolecular Resource Facilities (ABRF) surveys on microarrays atwww.abrf.org]. The printed cDNA microarray was largely developed from gene expression work originating in the laboratories of RO. Brown and R.W. Davis at Stanford University (Schena et al., 1995). Plans for the construction of the microarrayer and split pin designs were available at the Brown lab website at http //cmgm.stanford.edu/ pbrown/mguide/index.html. This enabled researchers to prepare their own microarrays appropriate for their particular experiments. 

The commercial success of the spotted microarray, like that of Affymetrix s GeneChip, is content-driven. In order to provide customers with comprehensive gene expression microarray products, manufacturers must obtain gene-specific annotated sequences covering genomes of major interest to the scienhfic community (e.g., genomes of humans, yeasts, and mice). 

IMAGE (Integrated Molecular Analysis of Genomes and Their Expression) consortium collection (http //image.llnl.gov/image/html/idistributors. shtml). The current U.S. distributors are  

American Type Culture Collection, Manassas, VA (www.atcc.org) 

Research Genetics, Carlsbad, CA (now owned by Invitrogen www. invitrogen.com) 

---