A two-step real-time RT-PCR protocol was developed to measure the mRNA levels of the studied genes in eight tissues of Atlantic salmon. For evaluation of the potential reference genes, raw Ct values are presented. The geNorm VBA applet for Microsoft Excel was used to determine the most stable genes from the set of tested genes [5] . The Ct values were transformed to quantities using standard curves, according to the geNorm manual. The gene expression stability (M) was calculated with the geNorm applet, and the genes were ranked from best to worst, based on the M value.