Thousands of papers have cited RNasin® Ribonuclease Inhibitors as the source of RNase protection since Promega introduced RNasin® Inhibitors over 35 years ago, making them the most trusted reagents for RNA protection. RNasin® RNase Inhibitors work by binding strongly to RNases, preventing them from degrading vulnerable RNA molecules during manipulation in the laboratory. Reliable RNase inhibitors satisfy three major criteria: 1) They protect RNA and do not introduce RNAses; 2) They are compatible with experimental conditions used in multiple applications; and 3) They work rapidly. RNAsin fulfills all of these criteria.
Introduction to RNase Inhibitors
Ribonuclease (RNase) contamination is always a concern when performing experiments involving RNA. Even with the cleanest of techniques, RNase contamination can happen and may have profound effects on data from downstream applications. High-quality, intact RNA is crucial to the success of sensitive applications such as RT-qPCR, RNA-protein binding assays, microarray analysis and RNA sequencing.
Although purified RNA may not contain RNases and could be perfectly intact, RNases can be introduced during downstream handling. RNases can be introduced into the laboratory in many ways, from bare hands to open windows and air vents, but the results are still the same: degraded RNA and, ultimately, compromised experiments. Pipets may be used for both plasmid work and RT-PCR reaction set-up and become a source of exogenous RNases. Even robotic liquid handlers used as multipurpose laboratory tools, at one time performing plasmid purifications and at another purifying RNA and assembling RT-PCR reactions, could become a source of RNase contamination.
There are numerous commercially available RNase inhibitors designed to protect sensitive, RNA-based experiments. Placental ribonuclease inhibitor is a 50kDa protein that inhibits RNase by binding it in a 1:1 ratio with an association constant greater than 1016 M–1 (1) . It is expressed as a single-chain polypeptide consisting of 460 amino acid residues and contains leucine-rich repeats, a motif commonly associated with protein:protein interactions. RNasin® Ribonuclease Inhibitor is a noncompetitive inhibitor of RNases A, B and C, human placental RNase and angiogenin. Although RNasin® Ribonuclease Inhibitor affects a broad spectrum of RNases, it does not inhibit other nucleases, reverse transcriptases or polymerases.
Promega offers Native and Recombinant RNasin® Ribonuclease Inhibitor, as well as RNasin® Plus, which offers greater oxidation resistance and is stable for up to 15 minutes at 70°C.
1. Dickson, K.A., Haigis, M.C. and Raines, R.T. (2005) Ribonuclease inhibitor: Structure and function. Prog. Nucleic Acid Res. Mol. Biol. 80, 349–74.