DNA modifying enzyme
For in vitro use only!
Unit Definition: One Kunitz unit is defined as the amount of enzyme required to produce an increase in absorbance of 260 nm of 0.001/min/ml at 25°C of highly polymerized DNA.
Shipping: shipped on blue ice
Storage Conditions: store at -20 °C
avoid freeze/thaw cycles
Shelf Life: 12 months
Form: liquid (Supplied in 10 mM Tris-HCl pH 7.5, 10 mM CaCl2, 10 mM MgCl2 and 50 % [v/v] glycerol)
Concentration: 2 units/μl
Activity: > 2500 units/mg protein
DNase I is commonly added to cell lysis reagents to remove the viscosity caused by the DNA content in bacterial cell lysates or to remove DNA templates from RNA produced by in vitro transcription.
DNase I removes unwanted DNA from cell lysates to improve protein extraction efficiency.
DNase I (RNase free), Deoxyribonuclease I is a single, glycosylated polypeptide that degrades single- and double-stranded DNA. The enzyme works by cleaving DNA into 5' phosphodinucleotide and small oligonucleotide fragments.
DNase I is used for application requiring the digestion of DNA in which it is crucial to avoid damage to RNA.
1x DNase I Reaction Buffer
Incubation at 37°C
10x DNase I Reaction Buffer:
100 mM Tris-HCl pH 7.6 (25°C)
25 mM MgCl2
5 mM CaCl2
DNase I is inactivated by heating to 65 °C for 10 minutes. High levels of monovalent ions such as Na+ and K+ (i.e. 100 mM) will decrease DNase I activity.
 The unit definition of 'Kunitz units' is increasingly replaced by 'Degradation Assay units'. One Degradation Assay unit is equal to 3 Kunitz units and defined as the amount of enzyme required to completely degrade 1 μg of plasmid DNA in 10 minutes at 37 °C in 10 mM Tris-HCl pH 7.5, 50 mM MgCl2 and 13 mM CaCl2.
Please click the black arrow on the right to expand the citation list. Click publication title for the full text.
Sambrook et al. (1989) Molecular Cloning: A Laboratory Manual, 2nd ed. New York: Cold Spring Harbor Laboratory Press 10.6
Tabor et al. (1997) DNA-Dependent DNA Polymerases. In: Current Protocols in Molecular Biology. Ausubel et al., eds. Wiley & Sons Inc. 3.5.4-6.
Pan et al. (1999) Ca2+- dependent activity of human DNase I and its hyperactive variants. Protein Sci. 8:1780.