DNase I（RNase Free） is a deoxyribonuclease that can randomly decompose single or double-stranded DNA and generate 5′-P end oligonucleotides of deoxyribonucleic acid. When Mg2+ is present, it can randomly generate cuts on double-stranded DNA; while in Mn2+ it can simultaneously cut double-stranded DNA to fragment DNA.
The Takara DNase I (RNase Free) enzyme is a highly purified DNase that lacks RNase activity, making it suitable for applications where RNA integrity must be preserved. It is supplied as a lyophilized powder (1,000 U) together with a 10× DNase I buffer.
The enzyme should be stored at –20 °C. The 10× buffer contains Tris‑HCl (20 mM, pH 7.5), NaCl (50 mM), CaCl₂ (0.1 mM) and 50 % glycerol. Typical protocols describe mixing the enzyme with the buffer and incubating at 37 °C for 20–30 min, followed by inactivation with EDTA and heat treatment. This manual is written in Chinese.
| 10× DNase I Buffer – Tris‑HCl | 20 mM (pH 7.5) |
|---|---|
| 10× DNase I Buffer – NaCl | 50 mM |
| 10× DNase I Buffer – CaCl₂ | 0.1 mM |
| 10× DNase I Buffer – Glycerol | 50 % |
| Enzyme activity unit | 1 Kunitz Unit |
The buffer contains Tris‑HCl 20 mM (pH 7.5), NaCl 50 mM, CaCl₂ 0.1 mM and 50 % glycerol.
Add 2.5 mM EDTA and heat the mixture at 80 °C for 2 minutes to inactivate the enzyme.
Incubate the reaction at 37 °C for 20–30 minutes in the provided buffer.