GEL-ELECTROPHORETIC FRACTIONATION OF RNAS BY PARTIAL DENATURATION WITH METHYLMERCURIC HYDROXIDE

The changes in agarose gel electrophoretic velocities of several RNAs of varying molecular weight and base composition with concentration of the denaturant, methylmercuric hydroxide (MMH), have been studied. At intermediate MMH concentrations, the mobility of any one species is intermediate between the native" (no MMH) and fully denatured (5 mm MMH) values. A + U-richer RNAs are partially denatured at lower concentrations of MMH than are G + C-richer RNAs. Electrophoresis at intermediate MMH concentrations is useful for resolving some RNA species that are not well resolved either in the absence of MMH or under fully denaturing (5 mm MMH) conditions. It is shown that it is possible to carry out MMH electrophoresis in polyacrylamide gels; this is useful for low molecular weight RNAs. An equation to correlate changes in mobility between the native and denatured states is proposed. © 1979."