Ribonuclease inhibitor.
Ribonuclease inhibitor (EC from human placenta inhibits different RNAse A-type enzymes (A, B, C) by binding noncovalently in 1:1 ratio. The enzyme does not inhibit RNase I, T1, T2, H, U1, U2, CL3 or S1 nuclease.
Unit definition
One unit inhibits 5 ng of RNAse A with efficiency of 50% using cyclic 2´,3´ CMP as a substrate.
Reaction conditions
Ribonuclease inhibitor should be added to give a final concentration of 1U/ µl. Presence of 1-10 mM DTT is required for activity. The enzyme can be inactivated by heating (>55°C), high salt concentration (e.g., 7 M urea) or addition of SDS.
Store at -20°C.
RNA isolation, cDNA synthesis, in vitro transcription/translation.

Quality control

activity, SDS-PAGE purity,assayed in RT-PCR.


1. Blackburn, P. (1979) J. Biol. Chem. 254, 12484.

Catalog #





Pack size

1.000 U

5.000 U





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