Endonucleases DNA-specific, dsDNase
Double-Strand Specific dsDNase (dsDNase) is ideal for fast and effective removal of contaminating DNA from PCR master mixes.
Taq polymerases are commonly contaminated by bacterial DNA. This is a problem in PCR based bacterial typing and detection as it might cause false positive results. The unique properties of dsDNase make it suited for removal of contaminating DNA from PCR master mixes prior to addition of DNA template.
In figure 1, a PCR master mix was treated with different amounts of dsDNase before performing a qPCR to measure the contaminating bacterial DNA in the master mix. ArcticZymes dsDNase effectively removed contaminating DNA below known levels of the assay detection limits.
The dsDNase from Arctic shrimp (Pandalus borealis) is recombinantly produced in Pichia pastoris. It cleaves phosphodiester linkages in DNA to yield oligonucleotides with 5’-phosphate and 3’-hydroxyl termini.
The specific activity is estimated to be 30 times higher than that of bovine DNase I. In the presence of magnesium as only divalent cation and using oligos as a substrate, the activity towards dsDNA is 5000-fold higher than towards ssDNA.
The unique double strand-specificity allows specific degradation of dsDNA while leaving shorter ssDNA as primers and probes essentially intact. Easy inactivation by moderate heat (65°C) allows addition of DNA intended for analysis directly after removal of contaminating DNA.
Figure 1. The dsDNase effectively removes contaminated DNA
The dsDNase effectively removes contaminated DNA:
A PCR master mix was preincubated with various concentrations of dsDNase. After treatment, no DNA was amplified in non-template controls.
Nucleic acid specificity has been tested towards double- and single-stranded DNA and RNA oligonucleotides. The specificity of dsDNase towards the substrate has been measured using 15-mer oligonucleotides with FAM at 5′ and DarkQuencher® 3′ (Eurogentec). The fluorescence is proportional to enzyme activity. Assay conditions: 25 mM Tris pH 7.5, 5 mM MgCl2, and 2 μM oligonucleotide.
Substrate Relative Activity
dsDNA 100%
ssDNA <0.03%
dsRNA <0.01%
ssRNA <0.01%
Double-Strand Specific dsDNase (dsDNase) is ideal for fast and effective removal of contaminating DNA from PCR master mixes.
Taq polymerases are commonly contaminated by bacterial DNA. This is a problem in PCR based bacterial typing and detection as it might cause false positive results. The unique properties of dsDNase make it suited for removal of contaminating DNA from PCR master mixes prior to addition of DNA template.
Norgen’s Viral Transport Medium is formulated to transport samples that are presumably infected with a virus. Viral Transport Medium is manufactured based on CDC formula and is offered in bulk to provide an option to readily assemble swab collection devices for sample collection.
Norgen’s Viral Transport Medium (VTM) is designed for safe and efficient transport of viral samples, including but not limited to those from nasal, throat, and other swabs. The VTM contains a balanced mix of Hank’s Balanced Salt Solution (HBSS), heat-inactivated fetal bovine serum (FBS), gentamicin sulfate, and amphotericin B to preserve the viability of viruses and prevent the growth of contaminating bacteria and fungi. The medium ensures the stability and viability of viruses, chlamydia, and mycoplasma for analysis using different techniques. In addition, the Viral Transport Medium eliminates the need to immediately process or freeze samples.
Storage Conditions and Product Stability
The Viral Transport Medium can be stored at 2-8°C for up to 1 year from the date of manufacturing without any reduction in performance.
Magnetic Beads (tRNA Purification)
Solid Phase Reversible Immobilization magnetic beads has been used for nucleic acids purification because they are effective, simple, and fast. The carboxyl groups coated beads are paramagnetic particles that reversibly bind to nucleic acid. However, there is a drawback for magnetic beads that it can only purify DNA/RNA that are 100 base pairs or longer. tRNA and other DNA/RNA fragments shorter than 100 base pairs are not effectively recovered. We have developed Magnetic Beads (tRNA Purification) to overcome the hurdle.
The Magnetic Beads (tRNA Purification) solves the tRNA and short DNA/RNA purification problem. The beads with our proprietary technology purify tRNA effectively by removing impurities and unwanted components such as dNTPs, detergents, salts, proteins, and other contaminants. The magnetic bead reagents can be used for oligo (>70 nt) applications.
Workflow without large RNA/DNA contamination
In the case of samples contaminated with RNA/DNA such as rRNA and DNA, our magnetic beads can effectively remove RNA/DNA that are 180 nt and larger. Purified tRNA are ideal for applications requiring high quality, as the fragments are free of impurities and contaminants.
Workflow with large RNA/DNA contamination
Comparison of tRNA and 70 nt oligos recovery. BioDynami beads (tRNA purification) successfully recovered DNA fragments both yeast tRNA and 70 nt oligos.
Recovery of tRNA and 70 nt oligos with BioDynami magnetic Beads (tRNA Purification). Yeast tRNA and 70 nt oligos were used as input. Input and recovered oligos were quantified with ssDNA Quantification kit (BioDynami Cat. # 40043) and RNA Quantification kit (BioDynami Cat. # 40044).
Depletion of larger RNAs. Left panel: depletion of 28S rRNA and 18S rRNA. Right panel: depletion of RNA of 180 nt and larger.
Features
Removal of unwanted components and other impurities
Purification of tRNA and oligos (>70 nt)
tRNA
RNA fragments 70 nt or longer
DNA/RNA hybrid fragments 70 nt or longer
Oligo and chimeric oligo 70 nt or longer
dsDNA fragments 70 bp or longer
ssDNA fragments 70 nt or longer
Removal of larger RNA/DNA contamination:
18S rRNA
28S rRNA
RNA/DNA> 180 nt
Solid Phase Reversible Immobilization magnetic beads has been used for nucleic acids purification because they are effective, simple, and fast. The carboxyl groups coated beads are paramagnetic particles that reversibly bind to nucleic acid. However, there is a drawback for magnetic beads that it can only purify DNA/RNA that are 100 base pairs or longer. tRNA and other DNA/RNA fragments shorter than 100 base pairs are not effectively recovered. We have developed Magnetic Beads (tRNA Purification) to overcome the hurdle.