Figure 3: Correlation of the matrix with SAGE libraries from tissues showing no inter- tissue correlation. Pearson product-moment correlation coefficients (vertical axes) calculated between each individual SAGE library and the QC expression matrix, showing a high quality match for all SAGE libraries. The intra-tissue correlation (with the stated tissue) and inter-tissue correlation (with other tissues) reveal the quality of the match between the two data types. All libraries show high correlation scores with the expected tissues of origin indicating correct library annotations and good expression data quality. The layout is identical to that shown in Figure 2. The result demonstrate that our QC matrix originally created based on EST expression performs equally well when allied to SAGE expression data.