Figure 3
From: Genomic selection of reference genes for real-time PCR in human myocardium
Determination of the ideal number of reference genes for normalization. Using the two most stable genes as a starting point (SRP14 and TPT1), genes are added sequentially (from most stable to least stable) until the pairwise variation between two sequential normalization factors drops below the recommended threshold of 0.15, indicating that the prior gene set is sufficient for accurate normalization. Variation greater than 0.15 indicates that the added gene has a significant effect and should preferably be included, provided it is stably expressed. This figure shows that the sixth most stable gene (RPS4X) is not required for reliable normalization of RT-PCR data.