Figure 4

Pairwise variation analysis to determination of the optimal number of the nine candidate reference genes. All pairwise variation (Vn/Vn + 1) were calculated via geNorm, and the values determined the minimum number of reference genes for accurate normalization in each experimental set. The Vn/Vn + 1 values below 0.15 indicate that an additional reference genes are not necessary for gene expression normalization.