Heat-Labile Double-Strand Specific DNase
(HL-dsDNase)
Main advantages with Heat-Labile dsDNase
- Double-strand DNA specific endonuclease
- Easily heat-inactivated by very moderate heat treatment
- High specific activity
- Useful for removal of DNA from RNA preps
Heat-Labile dsDNase is a genetically engineered version of dsDNAs that is rapidly and completely inactivated at moderately high temperatures. At only 55 °C, HL-dsDNase is completely inactivated after only 1 minute. This makes this product very useful for removal of DNA from RNA preparations, since the enzyme may be heat inactivated without risk of auto-degradation of RNA in the presence of magnesium.
Properties
Unit definition: One Unit is defined as an increase in absorbance at 260 nm of 0.001 per minute, using 50 mg/ml high MW DNA in 50 mM Na-acetate pH 5.0 and 5 mM MgCl2 (Kunitz, 1950).
Specific activity: 200 000 Kunitz Units/mg.
pH optimum: pH 7.5 (in Tris-HCl).
Storage buffer: 20 mM Tris-HCl pH 7.5, 2 mM MgCl2, 10 mM NaCl, 0.01% (v/v) Triton X-100, 50% (v/v) glycerol.
Reaction buffer: 20 mM Tris-HCl pH 7.5, 5 mM MgCl2. Dependent on magnesium ions for activity. Dependent on 1 mM DTT for inactivation.
Specificity towards double-stranded DNA
The specificity towards nucleic acid types is identical to that of dsDNase; activity towards ssDNA is less than 0.03% that of activity towards dsDNA. Activity towards ssRNA or dsRNA is less than 0.01 %.