Quantitative real-time polymerase chain reaction (RT-qPCR) has become an indispensable
technique for accurate determination of gene expression in variety of samples. Accurate and
reliable quantification, however, depends on a proper normalization strategy. Normalization with
multiple uniformly expressed reference genes is becoming the standard, although the most suitable
reference genes dependent on the used experimental factors as well as the tissue or cell type studied.
In this study, the stability of various reference genes was investigated in porcine hepatic tissue. The
study was conducted on Polish Large White, Polish Landrace, Pietrain, Pulawska and Duroc pigs
slaghtered at different ages. Nine reference genes (ACTB, B2M, GAPDH, HPRT1, RPL13A, SDHA,
TBP, TOP2B and YWHAZ) were investigated on 180 mRNA samples of porcine hepatic tissue.
Based on geNorm and NormFinder analysis, three most stable (HPRT1, TOP2B and TBP) and three
moderately (GAPDH, ACTB and SDHA) stable reference genes were identified. The study provides anew panel of reference genes for normalization of the expression of a gene of interest in porcine liver
tissue. It is concluded that the use of a single gene for normalization may lead to relatively large
errors, so it is important to use multiple control genes based on a survey of potential reference genes
applied to gene expression profiling studies of candidate genes for economic traits in pigs.