Use Deoxyribonuclease I (DNase I), Animal Component-Free (ACF) for routine tissue dissociation, to minimize cell clumping, and eliminate DNA contaminants from dissociation medium. Obtained from cultures free of animal-derived materials and purified by chromatography, this endonuclease consists of a single glycosylated polypeptide chain with two disulfide bonds. It preferentially cleaves phosphodiester linkages adjacent to pyrimidine nucleotides in both single- and double-stranded DNA, yielding polynucleotides with 5’-phosphate and 3’-hydroxyl groups (Bernardi et al.). DNase I has been used for DNA digestion in human cells and tissues such as microglia (Klegeris & McGeer), cartilage (Dunham & Koch), colon (Fukushima & Fiocchi), epithelium (Fukushima & Fiocchi), liver (Vatakis et al.), lung (Fujino et al.), neural cells (Fuja et al.), and stem cells (Kusuma et al.).