This array was developed in-house at NIEHS, and used for gene expression profiling experiments. A complete listing of the genes on this chip is available at the following Web site: http://dir.niehs.nih.gov/microarray/chips.htm cDNA microarray chips were prepared according to DeRisi et al., 1996, Nat. Genet. 14, 457-460. The spotted cDNAs were derived from a collection of sequence-verified clones that covered the 3` end of the gene and ranged in size from 500 to 2000 base pairs (Research Genetics). M13 primers were used to amplify insert cDNAs from purified plasmid DNA in a 100 5l polymerase chain reaction (PCR) mixture. A sample of the PCR products (10 microliters) was separated on 2% agarose gels to ensure quality of the amplifications. The remaining PCR products were purified by ethanol precipitation, resuspended in ArrayIt buffer (Telechem, San Jose CA) and spotted onto poly-L-lysine-coated glass slides using a modified, robotic DNA arrayer (Beecher Instruments, Bethesda MD).
