Ribonuclease A or RNase A; endoribonuclease purified from bovine pancreas. Important enzyme for the removal of RNA for RNA free DNA purification reactions such as plasmid DNA purification and genomic DNA purification, RNA removal from recombinant protein preparations, ribonuclease protection assays, mapping single-base mutations in DNA/RNA. Effectively cleaves the phosphodiester bond between the 5’-ribose of a nucleotide and the phosphate group attached to the 3’-ribose of an adjacent pyrimidine nucleotide which forms a 2’,3’-cyclic phosphate which is then hydrolyzed to the corresponding 3’-nucleoside phosphate.