For Northern blot analysis of high molecular weight RNA species, 4 µg of total RNA were resolved on agarose denaturing gels (6% formaldehyde/1.2% agarose in HEPES-EDTA buffer).

For Northern blot analysis of low molecular weight RNA species, 5 µg of total RNA were resolved on acrylamide denaturing gels (8% acrylamide-bisacrylamide 19:1/8 M urea in Tris-borate-EDTA buffer).