Dextran sodium sulfate inhibition of real-time polymerase chain reaction amplification: A poly-A purification solution

Background: Dextran sulfate sodium (DSS) induces experimental colitis and promotes colitis-associated cancer in rodents. Here we document potent inhibition of real-time quantitative polymerase chain reaction (qPCR) using cDNA from DSS-exposed mouse tissues, which complicates gene expression analysis. Methods: We characterize DSS inhibition of qPCR in-vitro and in a wide array of murine tissues following ingestion of DSS. We examine different approaches to RNA purification prior to cDNA synthesis in order to optimize real-time polymerase chain reaction amplification and gene expression analysis. Results: DSS inhibits qPCR amplification of cDNA between 1 and 10 nM. Orally administered DSS interferes with qPCR amplification of cDNA derived from multiple tissues. Poly-A purification of DSS-exposed RNA allows reliable and cost-effective gene expression analysis in DSS-exposed tissue. Conclusions: DSS is a potent inhibitor of real-time qPCR amplification and interferes with tissue-specific gene expression analysis in DSS-exposed mice. Poly-A purification of tissue-derived RNA results in reliable and cost-effective gene expression analysis in DSS-exposed mice.