dsDNase，250UNITS，SRE0118-250U，Sigma

General description

dsDNase is a heat-labile endonuclease that has a strong preference for double-stranded DNA. dsDNase can be heat inactivated by heat treatment at 15 min at 65˚C, or 20 min at 60˚C. The enzyme requires 1 mM DTT and pH ≥ 8 for complete inactivation.

Application

This dsDNase is a useful tool to remove contaminating DNA from PCR mastermixes.

Features and Benefits

• This nuclease has double-stand specificity, which allows specific degradation of dsDNA while leaving shorter ssDNA as primers.
• Easy inactivation by moderate heat (65°C) allows addition of DNA intended for analysis directly after removal of contaminating DNA.
• The specific activity is estimated to be 30 times higher than that of bovine DNase I.

Preparation Note

In solution.

Other Notes

One Unit is defined as an increase in absorbance at 260 nm of 0.001 per minute, using 50 µg/ml high MW DNA in 100 mM Na-acetate pH 5.0 and 5 mM MgCl₂.
The dsDNase is highly active in a temperature range of 20-40°C. It needs at least 2.5 mM Mg for activity and has an optimal pH at 7.5.