Fig. 3.

Purification of dsRNA from E. coli. (a) Agarose gel electrophoresis of purified in vitro transcribed dsRNA and ssRNA. Following in vitro transcription, 2 μg of dsRNA containing excess ssRNA were incubated with RNase T1 in both the presence and absence of 0.5 M NaCl and purified by SPE. (b) Agarose gel electrophoresis of extracted and purified dsRNA. Following TRIzol extraction of total RNA from E. coli expressing dsRNA samples were incubated with RNase T1 in both the presence and absence of 0.3 M NaCl as indicated prior to purification using solid phase extraction. Control experiments were performed using total RNA from non-induced E. coli. (c) IP RP HPLC chromatogram of purified dsRNA. Following TRIzol extraction the total RNA from E. coli was purified in a single step using RNase T1/DNase in conjunction with solid phase extraction prior to analysis using IP RP HPLC gradient condition 1 at 260 nm UV detection.