Nesvadbová M. author Knoll A. author text journal article 2011 The selection of reference genes is essential for gene expression studies when using a real-time quantitative polymerase chain reaction (PCR). Reference gene selection should be performed for each experiment because the gene expression level may be changed in different experimental conditions. In this study, the stability of mRNA expression was determined for seven genes: HPRT1, RPS18, NACA, TBP, TAF4B, RPL32 and OAZ1. The stability of these reference genes was investigated in the skeletal muscle tissue of pig foetuses, piglets and adult pigs using real-time quantitative PCR and SYBR green chemistry. The expression of stability of the used reference genes was calculated using the geNorm application. Different gene expression profiles among the age categories of pigs were found out. RPS18 has been identified as the gene with the most stable expression in the muscle tissue of all pig age categories. HPRT1 and RPL32 were found to have the highest stability in piglets and adult pigs, and in foetuses and adults pigs, respectively. The newly used reference gene, TAF4B, reached the highest expression stability in piglets. gene stability; reference genes; quantitative PCR; Sus scrofa; age categories of pigs; muscle tissue 10.17221/1428-CJAS https://cjas.agriculturejournals.cz/artkey/cjs-201105-0002.php https://cjas.agriculturejournals.cz/artkey/cjs-201105-0002.php continuing 56 5 213 216 2011 12121819 periodical academic journal