The purified RNAs were analyzed on a 20% nondenatured polyacrylamide gel (29:1 acryl:bisacryl ratio) in the 1Â TBE (Tris-Borate-EDTA) buffer. The gel was run at a constant voltage of 150 V for 8 h at room temperature. The results were visualized by the staining of ethidium bromide.