Determination of the optimal number of reference genes. Pairwise variation calculated by geNorm to determine the minimum number of reference genes for accurate normalization in all the samples (A), fruit developmental series (B), different genotypes (C), different storage time series (D), different exogenous regulator treatments (E), different tissues (F). Every bar represents change in normalization accuracy when stepwise adding more endogenous reference genes according to the ranking in Figure 2.
Tong et al. BMC Molecular Biology 2009 10:71 doi:10.1186/1471-2199-10-71