Comparative gel electrophoresis analysis of helical junctions in RNA.

Comparative gel electrophoresis provides information on the relative angles subtended between helical arms at a branchpoint in RNA. It is based upon the comparison of electrophoretic mobility in polyacrylamide gels of species containing two long arms, with the remaining one(s) being significantly shorter. Although the method currently lacks a really well-established basis of physical theory, it is very powerful, yet simple to apply. It has had a number of significant successes in RNA, DNA and DNA-protein complexes, and in all cases to date the results have stood the test of time and eventual comparison with crystallographic analysis.