Study for evaluating the effect of different microarray platforms on gene expression measurements

88 breast cancer samples were profiled on Affymetrix U133A and Plus2 microarrays. 88 tissue samples were taken from surgical specimens of patients without any prior systemic treatment. The samples were then chopped in pieces, mixed, split up in two equal parts and stored in RNA later for processing on both Affymetrix U133A and Plus2.0 microarrays.