The RNA Prestain Marker High is a RNA ladder for precise sizing of RNA molecules in denaturing agarose gels. The RNA Prestain Marker High is a visible molecular weight marker for ssRNA, consisting of six colored (blue and purple) nucleic acids. The six colored bands (apparent molecular weights are 200, 500, 1,000, 2,000, 4,000 and 8,000 bases) are suitable for monitoring denaturing agarose gel electrophoresis and blotting onto membranes. The RNA Prestain Marker High shows the same mobility as that of the RNA Marker High (Cat # R0003) on denaturing agarose gel electrophoresis (>90% accuracy, see table 1). The RNA Prestain Marker High is supplied in a ready-to-use mixture without requiring heating or the addition of a denaturing agent before use.