Background

Dextran Sulfate Sodium (DSS) is very commonly used in laboratories to induce colitis in rodents. Specifically, it mimics the clinical and histological features of human Inflammatory Bowel Disease (IBD) with Ulcerative Colitis (UC) characteristics. DSS is diluted in the drinking water and penetrates tissues. We have observed that contamination of RNA extracts with DSS prevented successful subsequent amplification processes from the colon and small intestine, but also blood and other tissues obtained from DSS-treated animals. We had previously shown that the presence of DSS in the samples inhibited reverse transcription and polymerase chain reaction amplification (Viennois et al., 2013). This inhibitory effect was observed in a dose depended manner by Kerr et al. and they suggested a poly-A-purification based technique to remove DSS from total RNA extract (Kerr et al., 2012). We hereby propose another efficient and economical method for purifying total RNA extracts from DSS traces based on lithium chloride (LiCl) precipitations. This method has been extensively used in our laboratory as well as in others (Chassaing et al., 2012, Li et al., 2016); however, no attempt has been taken to document the procedure in detail. Therefore, we provide a detailed description of LiCl purification procedure of total RNA primarily isolated from DSS-treated murine tissue with another method (Trizol, Spin column-based nucleic acid purification…).