Accuracy of expression ratios: (A) Accuracy of expression ratios as a function of hybridization time. The incubation time was varied from 4 to 42.5 hours for hybridizations containing a total of 20 μg of cRNA target (4 μg of labeled cRNA + 16 μg of unlabeled cRNA) versus 20 μg of labeled cRNA. (B) Examination of the relative error for two platforms as a function of the fold change. The relative error for the Affymetrix GeneChip data from Zhou and Abagyan is shown versus the relative error for the CodeLink data from the 2-fold dilution series in Figure 2. The GeneChip data be obtained at the following web site: http://carrier.gnf.org/publications/MOID/spike.html.