Modified from: http://www.promega.com/paguide/chap6.htm#RNaseAmountThis protocol was used to remove RNA from DNA preparations.The RNases commonly used in an RPA are RNase I , RNase T1 or a combination of RNase T1 and RNase A. RNase I cleaves after all four ribonucleotides, RNase T1 cleaves after G residues and RNase A cleaves after A and U residues. For most efficient cleavage of the single-stranded regions immediately adjacent to the double-stranded RNA, we recommend RNase I (RNase ONE™ Ribonuclease, Cat.# M4261). Use 1–10u RNase ONE™ Ribonuclease per 10μg of total RNA or 0.1–1u of RNase ONE™ Ribonuclease per 1μg of poly(A)+ RNA.