Figure 7. A scatter plot showing the results of comparative hybridization with the microarrays constructed with 96 duplicated housekeeping genes. (A) Comparison of RNA samples derived from the same origin indicates similar expression levels of housekeeping genes (Pearson's correlation coefficient, r = 0.94). (B) The result of microarray hybridization with RNA samples from dissimilar tissues reveals divergent transcriptional levels of the housekeeping genes (r = 0.70).