Figure 5

Upper panel: Δ-vs-<Σ>_set plot of the intensity data of one complete chip taken from the HG-U133 spiked-in experiment (Affymetrix): Probe intensity data (black dots), probe-set log-averaged data (light dots) and moving average over ~100 probe-sets (line). The latter plot is enlarged in the lower panel: It is called (raw) hook curve because of its characteristic shape. The N-, mix-, S- and sat-hybridization regimes are indicated (compare with Figure 2). The breakpoint is used to classify the probesets into absent and present ones (see text).