BLIRT RNase A (DNase Free)

RNase A specifically cleaves at the 3′-side of pyrimidine (uracil or cytosine) phosphate bonds

Name Part Number Pack Size
RNase A (DNase Free) RP145 50 mg
  RP145-25 25 mL


RNase A specifically cleaves at the 3′-side of pyrimidine (uracil or cytosine) phosphate bonds. Ribonucleases do not hydrolyze DNA, because the DNA lacks 2′-OH groups essential for the formation of cyclic intermediates [1,2]. The enzyme is active under a wide range of reaction conditions. At low salt concentrations (0 to 100 mM NaCl), RNase A cleaves single-stranded and double-stranded RNA as well the RNA strand in RNA-DNA hybrids. However, at NaCl concentrations of 0.3 M or higher, RNase A specifically cleaves single-stranded RNA [8]. RNase is supplied as a lyophilized powder.


- Source: bovine pancreas

- Specific activity: >2500 u/mg protein (>50 Kunitz units/mg protein)

- Molecular Weight: 13.7 kDa monomer

- The working concentration for RNase A is 1-100 µg/ml depending on the application.


- Plasmid and genomic DNA preparation [3, 4]

- RNase protection assays [3]

- Mapping single-base mutations in DNA or RNA [5, 6]

- Remove unspecifically bound RNA

- Analysis of RNA sequences

- Hydrolyze RNA contained in protein samples


1.     Blackburn, P., Moore S., Pancreatic ribonuclease, The Enzymes, V, (Boyer, P.D, ed.), Academic Press, New York, the third edition, vol. 15, 317-433, 1982.

2.     Raines, R.T., Ribonuclease A, Chem. Rev., 98, 1045-1065, 1998.

3.     Sambrook, J., Russell, D.W., Molecular Cloning: A Laboratory Manual, the third edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1.31-1.38, 2001.

4.     Sharma, R.C., et al., A rapid procedure for isolation of RNA-free genomic DNA from mammalian cells, BioTechniques, 14, 176-178, 1993.

5.     Myers R.M., et al., Detection of single base substitutions by ribonuclease cleavage at mismatches in RNA:DNA duplexes, Science 230, 1242-1246, 1985.

6.     Winter E., et al., A method to detect and characterize point mutations in transcribed genes: Amplification and overexpression of the mutant c-Ki-ras allele in human tumor cells, Proc. Natl. Acad. Sci. USA, 82, 7575-7579, 1985.

7.     Kunitz, M.A., A spectrophotometric method for the measurement of ribonuclease activity, J. Biol. Chem., 164, 563-568, 1946.

8.     Ausubel, F.M., et al., Current Protocols in Molecular Biology, vol. 1, John Wiley & Sons, Inc., Brooklyn, New York, 3.13.1, 1994-2005.

Storage Temperature

Lyophilized powder storage at -20ºC.

Recommended Reaction and Storage Buffers
- 50 mM Tris-HCl (pH 7.4) and 50% (v/v) glycerol (storage at -20ºC)

- 50 mM Tris-HCl (pH 7.4) (storage at +4ºC)

Unit Definition
One unit of the enzyme causes an increase in absorbance of 1.0 at 260 nm when yeast RNA is hydrolyzed at 37°C and pH 5.0. Fifty units are approximately equivalent to 1 Kunitz unit [7].


The most potent inhibitor is a ~50 kDa protein from cytosol of mammalian cells. Other inhibitors: uridine 2’,3’-cyclic vanadate, 5’-diphosphoadenosine 3’-phosphate and 5’-diphosphoadenosine 2’-phosphate [2], SDS, diethyl pyrocarbonate, 4 M guanidinium thiocyanate plus 0.1 M β-mercaptoethanol and heavy metal ions. Inactivated by phenol/chloroform extraction.

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