Ambion® RNase A is an endonuclease that specifically cleaves 3' of U and C residues. Affinity Purified RNase A is intended for critical applications when the absence of DNase and other nonspecific nuclease activities is essential. Supplied in one tube containing 1 mg (1 mg/mL). Note: This preparation contains RNase B, a carbohydrate isoform of RNase A. RNase A is rigorously tested for contaminating nonspecific endonuclease, exonuclease, and protease activity.