Gel Electrophoresis: Equal volumes of samples were mixed with RNA loading dye. Samples containing PEI were additionally treated with 4 µL of heparin (25 mg mL -1 ). Samples were heated at 60˚C for 10 min. A native 1% agarose gel was prepared in 1x Tris-Borate Buffer with a 1:10,000 dilution of SyberSafe. Samples were loaded into the gel and a potential of 80V was applied for 45 mins. Gels were imaged using a BioRad ChemiDock imaging system.