Analytical gel electrophoresis of high-molecular-weight RNA in acrylamide-agarose gels containing methylmercuric hydroxide

A method of electrophoresis combining the resolving power of acrylamide, the structural stability of agarose, and the denaturing properties of methylmercuric hydroxide has been developed for the analysis of high-molecular-weight RNA. Composite gels containing 0.5% ( w v) agarose, 10 mm methylmercuric hydroxide, and 1.8 to 2.4% ( w v) acrylamide were used to analyze the electrophoretic mobilities of RNA species ranging in molecular weights from 0.529 × 10⁶ to 2.0 × 10⁶. The migration of RNA was found to comply with the theoretical foundations established for the behavior of fully denatured nucleic acids in an electric field. Two RNA species separated by 1 mm on a composite-methylmercuric hydroxide gel containing 2.2% ( w v) acrylamide need differ in their molecular weights by as little as 34 bases at the molecular weight of 0.529 × 10⁶. Procedures are described for the detection and quantitation of ³H-labeled RNA that had been separated on these gels.