EXTRACTION OF DOUBLE-STRANDED-RNA FROM PLANT-TISSUES WITHOUT THE USE OF ORGANIC-SOLVENTS

Double-stranded RNAs (dsRNAs) are commonly isolated from plants and in sects with toxic organic solvents such as phenol and chloroform that d enature and remove proteins from aqueous solutions containing nucleic acids. This procedure was modified by replacing the toxic solvents wit h sodium dodecyl sulfate and potassium acetate (SDS/KOAc). Samples wer e homogenized in liquid nitrogen mixed with buffer and SDS at 65 C and then with KOAc at 0 C. A precipitate, consisting of SDS, KOAc, and pr oteins, was removed by centrifugation. The supernatant containing nucl eic acids was collected and subjected to standard CF-11 cellulose chro matography to separate dsRNAs from other nucleic acids. The SDS/KOAc m ethod produced comparable yields and purity of dsRNA products compared to the phenol/chloroform method and is considered a convenient, effec tive alternative for isolating dsRNA from plant tissues.