Understandably the mol. wt. of dsRNA markers would not be strictly
equivalent to dsDNA molecules but molecular weight is not the issue, strictly
speaking. Markers are used in reference to their length in base pairs and
why question was whether or not two equivalent LENGTH dsRNA and dsDNA
molecules would behave differently in,say, 1% agarose gels. A recent
contribution to the net suggests they would be different and I would be
interested in knowing something of the magnitude of that differentce.