DNase I

DNase I, RNase-free is an endonuclease that digests single- and double-stranded DNA. It hydrolyses phosphodiester bonds producing mono- and oligodeoxyribonucleotides with 5'- phosphate and 3'- OH groups.

The enzyme activity is strictly dependent on Ca²⁺ and is activated by Mg2+ or Mn2+ ions. In the presence of Mg²⁺, DNase I cleaves each strand of dsDNA independently, in a statistically random fashion. In the presence of Mn²⁺, the enzyme cleaves both DNA strands at approximately the same site, producing DNA fragments with blunt ends or with one or two nucleotide overhangs.

Applications include: Preparation of DNA-free RNA; Removal of template DNA following in vitro transcription; Preparation of DNA-free RNA prior to RT-PCR and RT-qPCR; DNA labeling by nick-translation in conjunction with DNA Polymerase I; Studies of DNA-protein interactions by DNase I, RNase-free footprinting; Generation of a library of randomly overlapping DNA inserts (reaction buffer containing Mn²⁺ is used).

Source: E.coli cells with a cloned gene encoding bovine DNase I.