Boxplots showing intensity distributions for each strip on each array. Panel (a) shows raw data output from BeadStudio on the log2 scale. Panel (b) shows array-level quantile-normalized data. Panel (c) shows strip-level quantile-normalized data. The first six arrays from the left come from the first chip, the second six arrays from the second chip and last six arrays from the third chip. The first strip of each array is red and the second strip is green. The two strips belonging to each array have the same sample name. Log-intensities greater than 10 are omitted from the plot to better show the main body of values.