RNase H (Ribonuclease H) is an RNA-specific endonuclease that cleaves the RNA of RNA/DNA hybrids. A minimum of four continuous base pairs of RNA/DNA hybrids is required for activity. RNase H cleaves RNA to release 5′-oligoribonucleotides. The enzyme does not degrade single-stranded nucleic acids, double-stranded DNA or double-stranded RNA.