Principal component analysis. PCA was performed on the whole transcript levels. The plot shows that there is consistent behaviour (clustering) across biological replicates of the same samples. The two major sources of variation in the data are the tissue effect, which approximately corresponds to the 1st principal component (horizontal axis), and the stage effect (vertical axis).
Revil et al. BMC Genomics 2010 11:399 doi:10.1186/1471-2164-11-399