Hydroxyl radical footprinting is a powerful technique often
employed in characterization of the tertiary interactions between
proteins and nucleic acids. Following the generation of a nucleic
acid “ladder” either by chemical or enzymatic
reactions, the radiolabeled products are traditionally separated
by denaturing gel electrophoresis and further quantified by
phosphorimaging techniques. Here we report the use of ion pair
reverse phase liquid chromatography to analyze the products
of an RNA footprinting reaction using fluorescently labeled
RNA molecules. This technique offers several advantages over
existing procedures, including rapid analysis, automation, and
direct quantification of the cleavage products without the need
to employ radiolabeling. To illustrate the resolving power of
this technique, we have analyzed the products of base hydrolysis,
generated from a fluorescently labeled RNA molecule and have
subsequently used this method to define the solvent accessibility
of the substrate strand as it docks with the hairpin ribozyme.