DESCRIPTION
Native RNase-Inhibitor from human placenta exerts ist inhibitory effect by binding non-covalently to RNases in a 1:1 ratio with an association constant of 1014. It is a protein with molecular weight of 51 kDa and inhibits common eukaryotic RNases including RNase A, RNase B, RNase C.
It does not inhibit RNase H, S1 Nuclease, SP6, T7 or T3 RNA polymerase, AMV or M-MLV Reverse Transcriptase, Taq DNA polymerase and RNase T1.
The enzyme is active over a broad pH range between 5 and 8, with a maximum activity at pH 7-8.

APPLICATION
Any application where eukaryotic RNase contamination is a potential problem:

Inhibition of RNA degradation in the following:
   in vitro transcription
   cDNA synthesis
   in vitro translation
   isolation of mammalian cell fractions that contain mRNA-protein complex
RNA amplification
RNA purification and storage.
Separation and identification of specific ribonuclease activities
Studies of tumor suppression

CONCENTRATION
5 units/µl

UNIT DEFINITION
One unit inhibits 5 ng of RNase A by 50% using cytidine 2',3'-cyclic monophosphate (cCMP) as a substrat.

STORAGE BUFFER
20 mM Hepes-KOH, 50 mM KCl, 8 mM DTT, 50% glycerol

STORAGE TEMPERATURE
-20°C

QUALITY CONTROL
Activity, SDS-PAGE purity, absence of endonucleases/nickases and exonucleases.

REFERENCES
1. BLACKBURN, P. (1979) J. Biol. Chem. 254:12484