dsDNase HL

• Highly active in a broad temperature range (10–47°C)
• Yields low temperature activity to protect RNA or proteins
• Highly active in typical buffer formulations and has a wide pH range with an optimum of 7.0–8.0
• Requires at least 2 mM Mg²⁺ ions for optimal activity
• Possesses irreversible inactivation at low temperature (15 minutes at 52°C, 1 mM DTT)

dsDNase HL (500 U) is a 43.3 kDa heat-labile recombinant endonuclease derived from a cold water eukaryotic organism expressed in Pichia pastoris. The enzyme displays high specific activity towards double-stranded DNA, leaving single-stranded DNA or RNA undamaged in standard conditions.

It is supplied with 20 mM Tris-HCl, pH 8.0; 20 mM NaCl; 2 mM MgCl₂ ; 1 mM CaCl₂ ; 50% (v/v) glycerol.

One unit is defined as the amount of enzyme that causes an increase in absorbance at 260 nm of 1.0 in 30 minutes at 37°C in 50 mM Tris-HCl buffer, pH 8.0 (25°C) supplemented with 5 mM MgCl₂, 0.1 mg/mL BSA and 0.5 mg/mL herring sperm DNA as a substrate.

dsDNase HL can be quickly inactivated by heat treatment in moderate temperatures. It is intended for applications where the presence of dsDNA influences experiments’ results in thermo-sensitive applications. It is also beneficial for the rapid and safe purification of RNA or protein samples from contaminating DNA.

The enzyme hydrolyzes phosphodiester linkages yielding oligonucleotides with a 5′-phosphate and 3′-hydroxyl groups.

Quality Control

Protein concentration was determined by densitometry of SDS-PAGE electrophoresis using Coomassie Blue detection assay.

The presence of RNase activity was determined after incubation of 5 U dsDNase HL with 1 μg of total eukaryotic RNA in a 20 μL volume for 1 hour at 37°C.

The presence of proteolytic activity was determined by SDS-PAGE with Coomassie Blue detection following incubation of 1 μg of BSA with 100 U of enzyme for 20 hours at 37°C.

A 1.575 mL reaction volume containing herring sperm DNA as a substrate is incubated for 30 minutes at pH 8 at 37°C with an enzyme that degrades DNA to acid-soluble oligonucleotides. One unit of the enzyme causes an increase in absorbance at A260 of 1.0.

This is used for applications such as:

• dsDNA digestion for plasmid and genomic DNA
• RNA and protein samples rapid purification
• PCR, qPCR master mixes and other diagnostic reagents decontamination
• Degradation of DNA template in transcription reactions

The acquisition of BLIRT by QIAGEN in the second quarter of 2022 paved the way for BLIRT’s expansion of R&D and manufacturing capabilities for customized and standardized recombinant enzymes and molecular biology reagents. Due to the transition, the rebranding process from BLIRT to QIAGEN is ongoing and the following resources still show BLIRT branding.
 
We assure you that the integration does not affect the quality, fit, form and function of the products.