DNase I

What it means: Inactivation describes how the enzyme is stopped once digestion is complete. EDTA-chelatable means the enzyme depends on divalent cations, so chelating them shuts it down.

Why it matters:

• Carrying active DNase into a downstream enzymatic step would degrade the DNA template you are trying to use.
• Chelation works without heating, which matters when the sample contains anything heat-labile.
• Because inactivation is chemical rather than thermal, it is fully reversible if magnesium is later added back — so the EDTA must be accounted for, not ignored.

How to interpret here: Stop the reaction by adding EDTA, or remove the enzyme by column purification. Avoid phenol-chloroform extraction where RNA is present, as it may cause degradation.

Tip: The added EDTA carries into the next reaction and chelates its Mg²⁺ too — account for it when setting up the following step.

What it means: Enzyme Source is the organism and tissue the enzyme is purified from. This is the classical bovine pancreatic DNase I, the standard non-specific endonuclease in molecular biology.

Why it matters:

• A long-established source means buffer conditions, unit definitions and expected digestion behaviour are documented across decades of published protocols.
• Animal-sourced enzymes matter for labs with material-origin restrictions, so the source belongs in the method section.
• Bovine pancreatic DNase I is non-specific, cutting both single- and double-stranded DNA as well as chromatin and RNA:DNA hybrids.

How to interpret here: Standard published DNase I protocols apply directly. Note that this grade is not certified RNase-free — for gDNA removal from RNA samples, use DNase I (RNase-Free), Cat. No. E091.

Tip: Record the bovine origin where sample provenance must be documented for regulatory or publication purposes.

What it means: Buffer Included describes the reaction buffer supplied with the enzyme. This product ships with 1.0 ml of 10X DNase I Reaction Buffer alongside 2,000 U of enzyme.

Why it matters:

• DNase I requires divalent cations, and the supplied buffer provides them at the concentration the enzyme was characterised in.
• Using an EDTA-containing buffer from another kit will chelate those cations and silently prevent digestion.
• Which cation dominates changes the outcome — Mg²⁺ gives nicks, Mn²⁺ gives double-strand breaks — so the buffer is not interchangeable.

How to interpret here: Dilute the 10X buffer ten-fold in the digestion reaction. Do not substitute a generic nuclease buffer.

Tip: Thaw and mix the buffer completely before pipetting; salts settle during frozen storage.