DNase I-ST

Cat. No.: D1522668

GRADE & PURITY Recombinant, Suitable for molecular biology, EnzymoPure™, RNase free, ≥90%(SDS-PAGE), expressed in Pichia pastoris;2 U/μl

Expression system

Pichia pastoris

Bioactivity

2 U/μl

Overview

This product is recombinant DNase I. Compared with the wild-type enzyme, it has been engineered to exhibit significantly enhanced salt tolerance, capable of completely digesting DNA in solutions containing 300 mM monovalent salt. This product is free of RNase contamination.

Components List

D1522668	Components	Appearance	1KU	Storage
D1522668A	DNase I-ST (2 U/μl)	Liquid	500μl	-20℃. Avoid freeze/thaw cycles.
D1522668B	10× DNase I-ST Buffer	Liquid	1.25ml	-20℃. Avoid freeze/thaw cycles.

Activity Definition

One unit (U) is defined as the amount of enzyme required to completely degrade 1 μg of pUC19 plasmid DNA in 10 minutes at 37℃.

Applications

1. In vitro transcription: Removal of template DNA after RNA polymerase-mediated in vitro transcription.

2. Removal of genomic DNA contamination from RNA samples.

3. DNase I footprinting for analyzing DNA-protein interactions.

4. Nick translation labeling of DNA in combination with DNA Polymerase I.

5. Construction of random DNA fragment libraries.

6. Partial digestion of genomic DNA as a positive control in the TUNEL assay for apoptosis detection.

Quality Control

Protein Purity

Determined by SDS-PAGE, the protein purity is ≥90%.

RNase Residue Detection

2 U of DNase I-ST is incubated with 500 ng of total RNA at 37℃ for 1 h. More than 90% of the RNA remains intact as determined by agarose gel electrophoresis.

Protocol

1. Removal of Genomic DNA Contamination from RNA Samples

Reaction Setup:

Component	Volume
RNA	1 μg
10× DNase I-ST Buffer	1 μl
DNase I-ST (2 U/μl)	0.5 μl
Nuclease-Free Water	up to 10 μl

Reaction Conditions: 37℃ for 15 min.

Inactivation: Column purification or phenol/chloroform extraction.

2. Removal of Template DNA after In Vitro Transcription

Procedure:

① Add 1 U of DNase I-ST per 1 μg of template DNA in the transcription reaction. The enzyme dosage can be optimized as needed. 

② Reaction Conditions: 37℃ for 15 min. 

③ Inactivation: Column purification or phenol/chloroform extraction.

Notes

1. Perform all operations on RNA samples in RNase-free tubes.
2. When using this product to remove DNA from RNA samples, Murine RNase Inhibitor can be added to the reaction system at a final concentration of 1 U/μl to protect RNA from degradation.
3. DNase I-ST is sensitive to physical denaturation. Do not vortex vigorously when mixing.
4. For your safety and health, please wear a lab coat, disposable gloves, and a face mask during the experiment.

Specifications

Product Name

DNase I-ST

Synonyms

DNase I, Salt-Tolerant | DNase I-XT | DNase I-ST, RNase-free | Salt-Tolerant Deoxyribonuclease I | Salt-Tolerant DNase I | Recombinant Salt-Tolerant DNase I | RNase-free Salt-Tolerant DNase I

Grade

Recombinant, RNase free, Suitable for molecular biology, EnzymoPure™

Specifications & Purity

Recombinant,Suitable for molecular biology,EnzymoPure™,RNase free,≥90%(SDS-PAGE),expressed in Pichia pastoris;2 U/μl

Bioactivity

2 U/μl

Molecule Type

Enzyme

Product Line

Biological Products

Storage and Shipping

Concentration

expressed in Pichia pastoris;2 U/μl

Storage

Store at -20°C,Avoid repeated freezing and thawing

Shipped In

Ice chest + Ice pads

Stability And Storage

Store at -20℃ long term (24 months). Upon receipt, it is recommended to aliquot. Avoid freeze/thaw cycle.

Unit definition

One unit (U) is defined as the amount of enzyme required to completely degrade 1 μg of pUC19 plasmid DNA in 10 minutes at 37℃.

Application Protocols

Only tested application details provided by the manufacturer are reported here.

• Manufacturer-validated applications, recommended dilutions, and positive controls: Not specified for this item; refer to CoA/Spec Sheet.

General procedural guidance for DNase I (e.g., unit usage, buffers) is provided in the Reaction Conditions and Buffer Applications sections as literature context and is not product-specific.

Biological Roles

• General function (literature)

  • Deoxyribonuclease I (DNase I) is an endonuclease that cleaves phosphodiester bonds in DNA, producing 5′-phosphate and 3′-hydroxyl ends.
  • Requires divalent cations (commonly Mg2+; Ca2+ provides structural stabilization). Ionic environment modulates strand preference and cleavage pattern.

• Physiological context (literature)

  • Endogenous DNase I homologs participate in extracellular DNA turnover (e.g., maintenance of biofluid DNA homeostasis) and contribute to chromatin fragmentation under certain cellular conditions.

• Relevance to research workflows (general)

  • Widely used to remove residual DNA from RNA samples, reduce viscosity in lysates, and probe DNA–protein interactions.

• Specificity notes (literature)

  • Prefers certain DNA conformations and sequences under defined metal ion conditions; Mn2+ can broaden substrate range and alter cleavage.

Item-specific biological attributes (source organism, sequence variants, tags, glycosylation) are not specified for this product; refer to CoA/Spec Sheet.

Buffer Applications

This section focuses on practical buffer systems for DNase I use (general, literature). Item-specific formulations are not provided here.

• Typical working buffer (example; not product-specific)

  • 10–50 mM Tris-HCl, pH 7.5–8.0
  • 1–5 mM MgCl2 (required for catalysis)
  • 0.1–1 mM CaCl2 (enhances stability; optional depending on application)
  • 0–50 mM NaCl or KCl as needed; higher salt can reduce activity

• RNA protection context

  • For DNA removal from RNA, ensure all components are RNase-free. Include RNase inhibitors only if compatible (they typically do not affect DNase I but validate).

• Stopping/inactivation (general)

  • Add 5–20 mM EDTA to chelate Mg2+ and halt activity; follow with heat inactivation if compatible with your RNA/protein.
  • Alternatively, perform phenol-free cleanup (spin columns, magnetic beads) to remove enzyme.

• Limited digestion/footprinting buffers

  • Employ controlled ionic strength and defined Ca2+/Mg2+ ratios to achieve partial digestion for mapping DNA–protein contacts.

Note: Precise buffer recipes, stabilizers, or storage buffer for this item are not specified; consult the CoA/Spec Sheet.

Green Alternatives

• Enzymes as greener catalysts (general)

  • DNase I enables DNA removal under mild, aqueous, near-ambient conditions, reducing reliance on harsh chemicals (e.g., high-salt precipitations or chaotropes) and minimizing solvent waste.
  • Aqueous buffers at neutral pH and moderate temperature lower energy input and hazard potential compared with chemical depolymerization methods.

• Comparison to alternatives (general, literature)

  • DNase I vs non-specific endonucleases (e.g., Benzonase):
    • DNase I is RNase-free (item-specific designation), making it preferable for RNA workflows where RNA integrity must be preserved.
    • Non-specific nucleases digest both DNA and RNA and may not be suitable for RNA-focused applications but can be advantageous for total nucleic acid clearance in bioprocessing.
  • DNase I vs chemical DNA removal (phenol–chloroform, strong chaotropes):
    • DNase I avoids toxic organic solvents and reduces hazardous waste.
    • Enzymatic digestion can be followed by simple chelation/cleanup, often with lower environmental footprint.

• Trade-offs

  • Enzymes are biodegradable but sensitive to storage/transport conditions; cold chain requirements increase energy use.
  • Disposal of proteinaceous materials may require biohazard procedures depending on use context.

Note: No item-specific environmental certifications or solvent content are specified for this product.

Pharmaceutical Uses

No therapeutic/clinical claims are made. The notes below describe general formulation/manufacturing roles for DNase-class enzymes; they are not item-specific specifications.

• Bioprocessing roles (general)

  • As a process aid to reduce host-cell DNA in biologics manufacturing (e.g., during clarification or downstream purification) to meet residual DNA guidelines.
  • Viscosity reduction in cell lysates to enhance filtration, chromatography, and mixing.

• Formulation considerations (general)

  • Enzyme introduction is typically transient; removal/inactivation is demonstrated by downstream processing and validated analytical assays.
  • Metal-ion dependence requires careful control of chelators and pH in process buffers.

• Regulatory notes

  • Process enzymes may be addressed in regulatory filings with information on source, purification, absence of adventitious agents, and clearance validation.

Item-specific regulatory status (e.g., pharmacopeial monograph, residual limits, endotoxin, host-cell protein content) is not specified for this item; refer to CoA/Spec Sheet and your quality unit.

Physical Properties

• Item-specific physical specifications

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • Extinction coefficient, activity units, buffer composition, protein concentration: Not specified for this item; refer to CoA/Spec Sheet.

• Not applicable to proteins

  • Boiling point, melting point, density, refractive index, SMILES/InChI-based properties do not apply to macromolecular enzymes.

• Literature/general properties of DNase I (not item-specific)

  • Typical monomer mass: ~29–38 kDa depending on species, sequence, and tags (literature ranges).
  • Optimum temperature: commonly near 37 °C for many recombinant DNase I variants; active over a broad range at reduced rates.
  • pH profile: near-neutral to slightly alkaline (often pH 7.0–8.5), buffer- and salt-dependent.
  • Metal ion dependence: requires Mg2+ for catalysis; Ca2+ stabilizes the enzyme and can alter cleavage pattern; Mn2+ can shift activity from endo- toward more random cleavage (literature).
  • Reaction outputs: 5′-phosphate and 3′-OH termini on DNA fragments.

Note: Values above are general literature guidance for DNase I enzymes and are not specifications of this specific lot. Always consult the product CoA/Spec Sheet for definitive physical/activity data.

Quality & Grades

• Item-specific quality designations (from Product Data)

  • Recombinant: Produced via recombinant expression for batch-to-batch consistency, reduced adventitious contaminants, and defined sequence/background relative to tissue-derived enzymes.
  • Suitable for molecular biology: Qualified for nucleic acid workflows where purity and activity are critical.
  • EnzymoPure™: Vendor quality designation indicating high enzymatic purity; typically implies stringent removal of host-cell proteins, nucleases, and process impurities. Specific acceptance criteria are not provided here—refer to CoA/Spec Sheet.
  • RNase free: Qualified to be free of detectable RNase contamination, supporting RNA workflows (e.g., RT-qPCR, RNA-seq prep). This is item-specific.

• Practical implications

  • Reduced risk of RNase carryover when treating RNA preparations to remove residual DNA.
  • Recombinant production enhances reproducibility of unit activity and cleavage patterns compared with crude preparations.

• What is not specified for this item

  • Specific activity (U/mg), unit definition, host expression system, tag/sequence details, endotoxin levels, protease testing, bioburden: Not specified for this item; refer to CoA/Spec Sheet.

• Recommended qualification on receipt

  • Verify performance in your assay context (e.g., DNA removal efficacy from RNA samples) using internal positive controls.
  • Retain lot-specific CoA and, if needed, request additional QC details (e.g., RNase detection method, sensitivity thresholds).

Reaction & Applications

• Item-specific notes

  • Grade: Recombinant, Suitable for molecular biology, EnzymoPure™, RNase free (supports RNA-focused workflows). Research use only.

• Representative applications (general, literature)

  • Removal of contaminating genomic DNA from RNA preparations prior to RT-qPCR, RNA-seq, or cDNA library construction.
  • Post-extraction DNA cleanup in protein or cell lysates where DNA viscosity impedes pipetting or chromatography.
  • DNase footprinting to map DNA–protein interaction sites under controlled, limited digestion conditions.
  • Generation of 5′-phosphorylated DNA fragments for cloning or ligation strategies after subsequent end-repair.
  • Reduction of DNA background in immunoassays or enzyme assays influenced by nucleic acid binding/viscosity.
  • Micrococcal/DNase-assisted chromatin accessibility assays (with method-specific validation).

• Mechanistic notes (general)

  • Endonucleolytic cleavage of phosphodiester bonds in dsDNA/ssDNA; Mg2+ is essential for catalysis; Ca2+ stabilizes the enzyme.
  • Cleavage yields 5′-phosphate and 3′-OH termini.

• Practical tips (general)

  • Maintain RNase-free technique when working with RNA targets: use RNase-free consumables and solutions.
  • Optimize units of enzyme per μg DNA, incubation time, and temperature (commonly 37 °C) for your matrix.
  • Stop reactions by adding EDTA/EGTA to chelate Mg2+ and/or by heat inactivation if compatible; validate residual activity.

Note: Specific activity, unit definitions, and recommended working concentrations for this item are not provided here; refer to CoA/Spec Sheet.

Reaction Conditions

The following are general literature examples for DNase I and are not item-specific recommendations. Optimize for your sample type and consult the CoA/Spec Sheet for this product.

• Typical DNA removal from RNA prep (example)

  • Buffer: 10–20 mM Tris-HCl pH 7.5–8.0, 2–5 mM MgCl2, 0.1–0.5 mM CaCl2 (optional)
  • Temperature: 37 °C
  • Enzyme usage: Often on the order of 0.1–1 U per μg DNA; incubation 10–30 min
  • Stop: Add EDTA to 10–20 mM and heat-inactivate if compatible; or purify via column/beads

• Limited digestion/footprinting (example)

  • Titrate enzyme to achieve partial cleavage (seconds to minutes) at 0–4 °C or room temperature to slow reaction; include Ca2+ for stability and adjust salt to tune specificity.

• Viscosity reduction in lysates (example)

  • Add Mg2+ to working concentration; incubate 10–20 min at 25–37 °C with gentle mixing; monitor viscosity drop.

• Compatibility notes

  • Inhibited by EDTA/EGTA and by anionic detergents (e.g., SDS); non-ionic detergents at low levels may be tolerated (validate).
  • High salt (>200–300 mM) may reduce activity.

• Expected outcomes (general)

  • Conversion of high-MW DNA to oligonucleotides bearing 5′-phosphate/3′-OH ends, reducing viscosity and DNA-dependent interference.

Item-specific unit definition and activity are not specified for this product.

Safety & Handling

• GHS classification and hazard statements

  • Signal Word / H-Statements / Pictograms: Not specified for this item; refer to SDS.

• General laboratory safety for protein enzymes (guidance)

  • Handle in a biosafety cabinet when working with potentially contaminated biological materials.
  • Avoid inhalation of lyophilized powders and aerosols; proteins may be respiratory sensitizers in susceptible individuals.
  • Prevent skin/eye contact; wear appropriate PPE: lab coat, nitrile gloves, and safety glasses.
  • Use sterile, RNase/DNase-free plasticware when maintaining RNase-free conditions.

• Incompatibilities and stability (general)

  • Avoid proteases and harsh denaturants (e.g., SDS, high concentrations of urea/guanidinium) unless intentionally inactivating the enzyme.
  • Metal chelators (e.g., EDTA, EGTA) will inhibit DNase I by sequestering required divalent cations.
  • High ionic strength and extreme pH can reduce activity.

• First-aid overview (guidance; defer to SDS)

  • Inhalation: Move to fresh air; seek medical attention if symptoms occur.
  • Skin/eye contact: Rinse with water for at least 15 minutes; remove contaminated clothing; obtain medical advice as needed.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.

Always consult the product SDS and institutional biosafety policies for authoritative safety information. Research use only.

Solvent Selection

This product is a protein enzyme used in aqueous buffers; conventional organic solvent selection guidance for small molecules does not apply.

• Applicability note

  • DNase I functions in water-based buffers; organic solvents generally denature or inactivate the enzyme. If present at all, organic cosolvents should be minimal and validated empirically.

• Buffer compatibility (general, literature)

  • Typical working buffers are near neutral pH (e.g., 10–50 mM Tris-HCl, pH 7.5–8.0) with divalent cations (e.g., 1–5 mM MgCl2; ~0.1–1 mM CaCl2 for stability).
  • Chelators (EDTA/EGTA) inhibit activity by removing required divalent ions; use chelation only for intentional inhibition/stop steps.
  • High ionic strength (≥200–300 mM NaCl) can reduce binding/cleavage efficiency on some substrates.

• When to choose DNase I vs alternatives (general)

  • Choose DNase I for rapid degradation of DNA in RNA preps, protein extracts, and surface decontamination of DNA (with appropriate inactivation/cleanup).
  • Alternatives include non-specific endonucleases (e.g., Benzonase/Serratia nuclease) that also digest RNA; DNase I is preferred when preserving RNA is critical due to RNase-free qualification.

Note: Any cosolvent tolerance and precise buffer formulations are not specified for this item; consult CoA/Spec Sheet and validate in your system.

Storage & Reconstitution

• Item-specific storage and shipping

  • Storage Conditions: Store at -20 °C. Avoid repeated freezing and thawing (from Product Data).
  • Shipped In: Ice chest + ice pads (from Product Data).
  • Research Use Note: For research use only.

• Handling best practices (general)

  • Upon receipt, keep frozen. If frequent use is expected, prepare single-use aliquots on ice to minimize freeze–thaw cycles.
  • Maintain RNase-free conditions when aliquoting to preserve RNase-free status (use certified RNase/DNase-free tubes and tips).

• Reconstitution and formulation

  • Appearance and supplied form (liquid vs lyophilized) are not specified for this item; refer to CoA/Spec Sheet for exact instructions.
  • If lyophilized (general guidance): Reconstitute on ice with sterile, RNase-free buffer recommended by the CoA; avoid vigorous vortexing to limit foaming/denaturation.
  • If supplied in glycerol (general): Store at -20 °C; enzymes in 40–50% glycerol typically remain unfrozen and are stable for repeated access—confirm with CoA before adopting this practice.

• Inactivation/disposal (general)

  • To inactivate before disposal or downstream steps, chelate Mg2+ with EDTA and/or apply heat as compatible; follow institutional biosafety waste procedures.

Any lot-specific stabilizers, concentration, or compatible storage buffers are not specified for this item; consult the CoA/Spec Sheet.

Structure & Identity

Recombinant DNase I-ST is a protein endonuclease; small-molecule identifiers (CAS, SMILES) are not applicable to enzymes.

• Item-specific identifiers

  • SKU: D1522668
  • Product Name: DNase I-ST
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not applicable for proteins; not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not applicable for proteins; not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula: Not applicable as a single empirical formula for a recombinant protein; sequence-dependent and not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general, literature)

  • DNase I is a monomeric endonuclease protein composed of a polypeptide chain that folds into an α/β structure with a catalytic site requiring divalent cations (typically Mg2+; Ca2+ stabilizes).
  • Active site residues coordinate metal ions and water to hydrolyze phosphodiester bonds in DNA, producing 5′-phosphorylated oligonucleotides.
  • No stereocenters in the small-molecule sense; chirality derives from L-amino acid residues in the protein sequence.

• Functional description (general, literature)

  • Catalyzes endonucleolytic cleavage of dsDNA and ssDNA; activity is modulated by ionic strength and divalent metal composition.
  • RNase-free specification (item-specific) indicates the preparation is qualified to be free of RNase contamination for RNA-focused workflows.

Synthetic Utility

While not a reagent for classical organic synthesis, DNase I is a valuable biocatalyst in nucleic acid workflows.

• Utility in molecular construction/deconstruction (general)

  • Controlled fragmentation of DNA to generate substrates for cloning, end-repair, or library preparation after subsequent processing.
  • Removal of template DNA after in vitro transcription to yield RNA free of DNA contaminants.
  • Preparation of chromatin or nucleoprotein samples with tuned DNA length for structural studies.

• Retrosynthetic/strategic role

  • Enables orthogonal removal of DNA without damaging RNA or most proteins, simplifying downstream purification under mild, aqueous conditions.

• Integration with other enzymes

  • Pair with phosphatases/kinases and polymerases for end polishing, labeling, or adapter ligation workflows.

Item-specific activity units, kinetic constants, and sequence details are not provided; consult CoA/Spec Sheet for operational parameters.

Target Specificity

Only item-specific target/clone/epitope data are reported in this section.

• For this product: Not specified for this item; refer to CoA/Spec Sheet.

Note: DNase I is an enzyme, not an antibody; antigen/epitope/clone/isotype fields are not applicable.