Ambion® RNase A is an endonuclease that specifically cleaves 3' U and C residues. Affinity-purified RNase A can be used in critical applications when the lack of DNase and other non-specific nuclease activity is critical. Supplied in a tube containing 1 mg (1 mg/mL). Note: This preparation contains RNase B (a carbohydrate isomer of RNase A). Rigorous testing of RNase A for contaminating non-specific endonuclease, exonuclease and protease activities.