HPLC PURIFICATION OF RNA FOR CRYSTALLOGRAPHY AND NMR

Homogeneous preparations of milligram quantities of RNA are a prerequi site for their characterization by biophysical methods such as crystal lography or NMR spectroscopy. Methods for obtaining milligram quantiti es of pure synthetic RNA are described in this paper. These methods em ploy anion exchange HPLC for purifying full-length sequence from failu re sequences and incompletely deprotected material. RNA molecules with little or extensive amounts of secondary structure could be purified. In cases where the RNA molecule was tightly folded, the cation in the eluent buffer influenced both the distinction of the peaks during chr omatography and the final folded conformation. Finally, two RNA sequen ces were chemically synthesized, deprotected, purified, and crystalliz ed using this methodology.