A non-phenol–chloroform extraction of double-stranded RNA from plant and fungal tissues

Double-stranded RNA (dsRNA) molecules of viruses are found in nature at a very high frequency. Their detection in plants and fungi has been carried out with difficulty due to the complicated dsRNA extraction techniques used commonly which includes phenol–chloroform extractions. In this study, an extraction method for isolation of dsRNA is described that is free of phenol and chloroform. A lysis buffer, containing β-mercaptoethanol and polyvinylpolypyrrolidone (PVPP-40), was added to homogenised tissues and the subsequent supernatant was filtered through a cellulose CF-11 mini-column. DsRNA molecules were separated based on the differing affinity of nucleic acids for the cellulose CF-11 resin in 20% ethanol buffer. This easy, rapid and cheap technique has been successfully tested on fungi and plants containing different dsRNA virus molecules, indicating the possibility of a wide use of the method.