A, experimental design. B&C&D, correlation of log2 intensities within and between protocol groups. B&C, scatter plots of log2 signal intensities from a pair of replicates treated with the OneRA and the TwoRA protocol respectively. D, scatter plot of log2 signal intensities averaged across the OneRA replicates versus that from the TwoRA replicates. The coefficient of correlation (r) value is given for each pair. Similar results were obtained with the SN and SA sample groups.