Can RNA and DNA ladders be used interchangeably?

DNA and RNA ladders, also termed markers, are used as the standard(s) that run concurrently with the sample in gel electrophoresis. These ladders are composed of a solution of fragments of known sizes that act as molecular weight identifiers, and help to estimate the sizes of fragments in the test samples. While they serve similar purposes, RNA and DNA ladders are specific to their respective nucleic acids and cannot be used interchangeably. RNA migrates faster than DNA throughout the gel. RNA markers can also exist in various forms including single-stranded (ssRNA), double-stranded (dsRNA), microRNA, and mRNA.