RNase Inhibitor, Human Placenta is a recombinant human placental protein which specifically inhibits ribonucleases (RNases) A, B and C (1). It is not effective against RNase 1, RNase T1, S1 Nuclease, RNase H or RNase from Aspergillus. In addition, no inhibition of polymerase activity is observed when RNase Inhibitor, Human Placenta is used with Taq DNA Polymerase, AMV or M-MuLV Reverse Transcriptases, or Phage RNA Polymerases (SP6, T7, or T3).