A cetyltrimethylammonim bromide-based method to extract low-molecular-weight RNA from polysaccharide-rich plant tissues.

RNA extraction from specific organs and tissues is a preliminary step for many studies in plant molecular biology. However, some plant tissues of relevant biological and economical interest accumulate large quantities of polysaccharides, which complicate the isolation of good quality RNA. Here we report modifications to the CTAB method that make it more efficient for the isolation of LMW RNA. In the modified method, LiCl precipitation is replaced by isopropanol precipitation, while additional chloroform extractions are required to remove the polysaccharides. A PEG precipitation step is included to enrich the low molecular weight RNA fraction and to further purify the extracts.