Electrophoresis of RNA Denatured with Glyoxal or Formaldehyde

The first successful method for electrophoretic analysis of the full size range of cellular RNA molecules was described by Loening (1 ), and its introduction allowed for major advances, most particularly in the molecular biology of eukaryotic organisms. The method had, nevertheless, two significant disadvantages in that the gels (composed of acrylamide at very low concentrations) were mechanically fragile, and the migration of RNA molecules did not necessarily reflect their size because RNA secondary structure was not disrupted.