Distribution of probe intensity CV in the five conditions used for the experimental validation of probes. The distributions of probe intensity CV are presented in a series of five boxes (interquartile range) and whiskers plots. Hybridizations were performed on microarray v.2 with the cRNAs prepared from the five conditions (M24h, M48h, M96h, C24h, C48h) and labeled with Cy3. Each condition consisted of 4 biological replicates. The CVs were computed as indicated in Additional file 1. The median CV is 0.13, 0.10, 0.19, 0.12 and 0.11 for M24h, M48h, M96h, C24h and C48h, respectively.