PMC

Low average M values indicate high stability and high average M values indicate less stability.

Box plot of threshold cycle levels of candidate genes for human-chimpanzee samples across combined tissues: skeletal muscle, liver, and cerebral cortex.

The optimal number of control genes was determined by pairwise variations (V_n/n+1) between the normalization factors NF_n and NF_n+1. The black arrows indicate the optimal number of genes to use for RT-QPCR normalization. For each tissue, the inclusion of a fourth gene does not significantly change the normalization factor. For all tissues combined, the use of a fourth gene has a large effect on the normalization factor.