Figure 4

BABAR -generated boxplots showing Salmonella gene expression for the IHF dataset [22]. The figures plot M-value versus microarray identity. Gene expression values were obtained for wild-type Salmonella (white boxplots), IHFα mutant (light grey boxplots), IHFβ mutant (grey boxplots) and the double IHF mutant (dark grey boxplots) prior to BABAR processing (A), after background correction with 'within arrays' block-by-block data centering (B), cyclic loess with averaging of the log₂-ratios (C), and final centering of the data representing the processed output of BABAR (D). Each box highlights the median and characterises the range of 50% of the data for each microarray; circles show individual genes that are outliers.