Lyo NZY Ribonuclease Inhibitor is a freeze-dried enzyme preparation provided with an optimized reconstitution buffer designed to confer maximal levels of stability and enzymatic activity. The enzyme is subjected to rigorous purification protocols to ensure optimal performance. Lyo NZY Ribonuclease Inhibitor inhibits the activity of ribonucleases (RNases; EC 3.1) of the pancreatic type, such as RNase A, RNase B and RNase C, by binding them noncovalently in a 1:1 ratio. NZY Ribonuclease Inhibitor is useful in any application where RNase contamination is a potential problem. For instance, it can be used to protect template RNA in cDNA synthesis reactions, RT-PCR or in vitrotranscription/translation, as well as to protect viral RNA during in vitro replication. In addition, it will inhibit RNases during RNA isolation and purification and during RNase-free antibodies preparation. NZY Ribonuclease Inhibitor is not active against RNase 1, RNase T1, RNase T2, S1 nuclease and RNase H.