Micrococcal Nuclease is an endonuclease that preferentially digests single-stranded DNA or RNA, especially at AT- or AU-rich regions. The enzyme will also digest double-stranded DNA or RNA, making it an essential component of chromatin immunoprecipitation (ChIP) assays. Micrococcal Nuclease digests 5'-phosphodiester bonds of DNA and RNA, yielding 3'-phosphate mononucleotides and oligonucleotides. This enzyme requires Ca2+ as a cofactor for its activity and is completely inactivitated by EDTA or EGTA.