DNase I, 100 mg

An endonuclease enzyme formulation provided as 100 mg of lyophilized DNase I powder from STEMCELL Technologies. DNase I nonspecifically cleaves phosphodiester bonds in single- and double-stranded DNA, generating 3'-hydroxyl oligonucleotides and mono- or oligonucleotides that are easily removed during downstream purification steps.

The enzyme is widely used to remove contaminating genomic DNA from RNA preparations, digest extracellular DNA released during tissue dissociation, and prevent cell clumping in single-cell suspension workflows. Calcium ions are required for activation while magnesium ions support catalytic activity, with optimal activity typically observed at 37 °C in standard reaction buffers containing MgCl2 and CaCl2. The enzyme is also active at lower temperatures for gentle applications such as chromatin digestion.

Each vial is stored at -20 °C to preserve enzymatic activity and reconstituted to desired stock concentrations before use. Working concentrations commonly range from 1 to 10 U/mL for routine DNA digestion in cell culture and sample preparation applications. Reconstituted aliquots may be frozen for short-term storage and refrozen once, though repeated freeze-thaw cycles should be avoided to maintain full activity.