RNase R is an E. coli exoribonuclease which exhibits 3'-to-5' exonuclease activity, efficiently digesting nearly all linear RNA species. This enzyme does not digest circular, lariat, or double stranded RNA with short 3' overhangs (less than seven nucleotides). As such, this enzyme is ideally suited to the study of lariat RNA produced by traditional splicing, as well as circRNAs which arise through back-splicing. By removing linear RNAs from cellular or RNA extracts, RNase R greatly facilitates the identification of circular species through RNA-sequencing. This enables researchers to probe the landscape of splicing events with greater depth.