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Ribonuclease R (RNase R)

Ribonuclease R includes both the enzyme and an optimised 10X Reaction Buffer.

Ribonuclease R (RNase R)

A 3´ to 5´ exoribonuclease that digests all linear RNAs except lariat or circular RNA structures.
  • Specific: Digests all linear RNAs but does not digest lariat or circular RNA structures, or double stranded RNA with 3' overhangs shorter than seven nucleotides
  • Heat Inactivated: Heat at 65 °C for 20 minutes to kill enzyme activity
  • Valuable: Use the unique properties of this exoribonuclease to study alternative splicing and gene expression

Size: 250 units

Item ID RNR07250
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Product information

Ribonuclease R (RNase R) from E. coli is a magnesium-dependent 3´ to ;5´ exoribonuclease that digests essentially all linear RNAs but does not digest lariat or circular RNA structures 1,2, or double stranded RNA with 3´ overhangs shorter than seven nucleotides. 2 Most cellular RNAs will be digested completely by RNase R, with the exception of tRNAs, 5S RNA, and intron lariats (Figure. 1). The 3´ tails of lariats will be trimmed by RNase R to the branch point nucleotide, where there is a 2´,5´-phosphodiester linkage. Lariats are produced during pre-mRNA splicing of intron regions and can be isolated from a mixture of total RNA by digestion with RNase R. The MasterPure™ RNA and Yeast RNA Purification Kits are ideal for such total RNA preparations.

  • Alternative splicing and gene expression studies.
  • Intron cDNA production.
  • Intronic screening of cDNA libraries.

Lariat RNAs isolated using this method can be used as a template to produce labelled cDNA as a target for microarrays containing potential intron sequences, or for tiling arrays containing overlapping regions of complete chromosomes or genomes. The cDNA produced will not be a linear representation of the intron, but the sequences contained in it will be intron-derived.

rnase r

Figure 1. Schematic overview showing processing of intron lariats by RNase R.


  1. Suzuki, H. et al. (2006) Nucleic Acids Res. 34, 63.
  2. Vincent, H.A. and Deutscher, M. P. (2006) J. Biol. Chem. 281, 29769.

Note: RNase R requires low (0.1-1.0 mM) magnesium concentrations for activity. Low EDTA concentrations in substrate RNA solutions can negatively affect RNase R activity. Additional MgCl 2 up to 1 mM final concentration can be used to compensate for EDTA in the substrate. Optimal activity is at 37 °C.

Unit Definition: One unit of RNase R converts 1 µg of poly(A) into acid-soluble nucleotides in 10 minutes at 37 °C under standard assay conditions.

Storage Buffer: RNase R is supplied in a 50% glycerol solution containing 50 mM Tris-HCl (pH 7.5), 100 mM NaCl, 0.1 mM EDTA, 1 mM DTT, and 0.1% Triton® X-100.

RNase R 10X Reaction Buffer: 0.2 M Tris-HCl (pH 8.0), 1 M KCl, and 1 mM MgCl2.

Quality Control: RNase R is function-tested in a reaction containing a mixture of linear and circularized RNA oligonucleotides. Only the linear RNA is digested.

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