Murine RNase Inhibitor is a recombinant protein expressed and purified from E. coli. It specifically binds to RNase A, B, and C in a 1:1 ratio via non-covalent interactions, effectively inhibiting their activity and protecting RNA from degradation. However, it is not effective against RNase 1, RNase T1, S1 Nuclease, RNase H, or RNases derived from Aspergillus. This inhibitor has been validated in RT-PCR, RT-qPCR, and in vitro transcription (IVT) mRNA applications, and is compatible with a wide range of commercial reverse transcriptases, DNA polymerases, and RNA polymerases.

The amount of murine RNase inhibitor required to inhibit the activity of 5 ng of ribonuclease A by 50% was defined as one unit (U).

Avoid vigorous shaking or stirring, as it may lead to enzyme inactivation.
Optimal temperature range: 25°C-55°C. The inhibitor is inactivated at temperatures ≥65°C.
Not effective against RNase H, RNase 1, or RNase T1.
Active across a broad pH range (pH 5-9), with optimal activity observed at pH 7-8.
Since ribonucleases often retain activity under denaturing conditions, it is important to avoid denaturing RNase inhibitor-RNase complexes. Exposure to temperatures above 50°C or high concentrations of urea or other denaturing agents can release active ribonucleases from the complex.

Exonuclease Activity: 40 U of murine RNase inhibitor with 1 μg λ-Hind III digest DNA at 37°C for 16 hours yields no degradation.
Endonuclease Activity: 40 U with 1 μg λDNA at 37°C for 16 hours yields no degradation.
Nicking Activity: 40 U with 1 μg pBR322 at 37°C for 16 hours yields no degradation.
RNase Activity: 40 U with 1.6 μg MS2 RNA for 4 hours at 37°C yields no degradation.
E. coli DNA: 40 U screened by TaqMan qPCR for E. coli 16S rRNA. Genomic DNA contamination ≤0.1 pg/40 U.

Ship with ice packs. Store at -20°C. Avoid repeated freeze-thaw cycles. Product is stable for 2 years under recommended storage conditions.