Ribonuclease Inhibitor (RNase Inhibitor) is a recombinant protein. It inhibits different RNases (A, B, C) by binding non-covalently in a 1:1 ratio, with an association constant of 10(e14). RNase Inhibitor is useful in any applications where the presence of RNases is a potential problem. RNase Inhibitor is tested for activity, SDS-PAGE purity, and the absence of endonucleases, nickases and exonucleases.