QIAGEN RNase Inhibitor is a protein of nonhuman origin that binds noncovalently to, and inactivates, a variety of ribonucleases (e.g., RNase A, B, and C). It does not interfere with RNase T1, T2, H, U1, U2, or CL3. It is a polyclonal antibody that is highly active and inhibits more than 90% of RNase activity, whereas human placental RNase inhibitor (HPRI) inhibits only 50%. For this reason, QIAGEN RNase Inhibitor can be used at lower concentrations compared to other RNase inhibitors. In addition, QIAGEN RNase Inhibitor is stable over wide pH and temperature ranges and at varying dithiothreitol (DTT) concentrations. Titration is optimized for the highest stability and activity, and the solution is provided ready-to-use for maximum ease-of-use.