Figure 2

Analysis of candidate EC genes using geNorm. (A): Average expression stability values of eligible EC genes. Expression stability of the control genes as calculated by geNorm. Stability value M is based on the average pair-wise variation between all genes. The least stable gene with highest M value was excluded and M value recalculated till end up with the most stable pair. (B): Determination of optimal number of control genes for normalisation. The GeNorm programme calculates a normalisation factor (NF) which is used to determine the optimal number of EC genes required for accurate normalisation. This factor is calculated using the variable V as the pairwise variation (Vn/Vn + 1) between two sequential NFs (NFn and NFn + 1). To meet the recommended cut off V-value which is the point at which it is unnecessary to include additional genes in a normalisation strategy. The recommended limit for V value is 0.15 but it is not always achievable. In this instance, the GeNorm output file indicated that the optimal number of genes required for normalisation was three.