evaluation of β-actin as a reference gene for comparative expression analysis of equine adipose- and bone marrow-derived mesenchymal stem cells by qrt-pcr

background bone marrow and adipose tissue are two main sources of mesenchymal stem cells (mscs). some of studies suggest that there are some differences in gene expression profile of mscs-derived from various tissues. to investigate gene expression profile by qrt-pcr, an appropriate reference gene with stable expression level should be chosen for normalizing data.  this study was designed to evaluate the stability of β-actin expression as a reference gene for studying comparative gene expression analysis of equine adipose- and marrow-derived mscs. materials and method: mscs were isolated from adipose tissue and bone marrow of two mares and cultured until passage 3 (p3). total rna of p3 cells was extracted and purity and quantity of rna was assessed. cdna was synthesized and qrt-pcr was performed in triplicate with β-actin primers. results: our analyses indicated that expression level of β-actin gene is different between adipose- and marrow-derived mscs significantly. mean ± sd of ct was 21.13 ± 0.96 and 16.02 ± 0.88   for bone marrow- and adipose derived mscs, respectively. conclusion: based on the results, it is suggested that β-actin is not a suitable gene for comparative gene expression analyses of equine adipose- and marrow- derived mscs. keywords: adipose, bone marrow, equine, β-actin, mesenchymal stem cells.