Histograms of BLAST results conducted on 8 selected genes. BLAST results were conducted on four up-regulated genes and four down-regulated genes. The histogram on the left (A) shows the amount of probe overlap for all probes in the 8 probe sets. Slightly more than half of the probes had no overlap. The rest of the probes had overlap of between 1 and 13 bases. The histogram on the right (B) shows the number of partial homologies for each of the probes. The median number of partial homologies over all 88 probes submitted to BLAST was 17, and first and third quartiles were 11 and 28, respectively. The search was restricted to organism Rattus norvegicus.