Figure 4
From: Two-stage normalization using background intensities in cDNA microarray data
MA plots before and after normalization. The first row shows the MA plots for original (before normalization), after global normalization, and after nonlinear LOWESS normalization, respectively (from left to right), The second row shows M(2)versus A plots after two-stage normalization for Y 1 , Y 2 , and Y 3 (from left to right), respectively. The third row shows MA plots for Y 4 , Y 5 , and Y 6 , respectively and the bottom row shows MA plots for Y 7 , Y 8 , and Y 9 , respectively. The two-stage normalization methods using Y 2 and Y 3 perform better than global and non-linear LOWESS normalization methods.