Circular RNA migration in agarose gel electrophoresis

Mol Cell. 2022 May 5;82(9):1768-1777.e3. doi: 10.1016/j.molcel.2022.03.008. Epub 2022 Mar 30.


Circular RNAs are garnering increasing interest as potential regulatory RNAs and a format for gene expression. The characterization of circular RNA using analytical techniques commonly employed in the literature, such as gel electrophoresis, can, under differing conditions, yield different results when attempting to distinguish circular RNA from linear RNA of similar molecular weights. Here, we describe circular RNA migration in different conditions, analyzed by gel electrophoresis and high-performance liquid chromatography (HPLC). We characterize key parameters that affect the migration pattern of circular RNA in gel electrophoresis systems, which include gel type, electrophoresis time, sample buffer composition, and voltage. Finally, we demonstrate the utility of orthogonal analytical tests for circular RNA that take advantage of its covalently closed structure to further distinguish circular RNA from linear RNA following in vitro synthesis.

Keywords: E-gel; RNase H; RNase R; circRNA; circular RNA; electrophoresis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrophoresis, Agar Gel / methods
  • Molecular Weight
  • RNA* / genetics
  • RNA, Circular* / genetics


  • RNA, Circular
  • RNA