Ambion DNase I (RNase-free) (EC3.1.21.1) is a non-specific endonuclease that degrades Double-stranded and single-stranded DNA and chromatin. It works by hydrolyzing phosphodiester bonds to produce mononucleotides and oligonucleotides with 5'-phosphate and 3'-hydroxyl groups. RNase-free DNase I is the purest type of existing enzymes and is recommended to degrade DNA without RNase. RNase-free is essential for maintaining the integrity of RNA. For example, DNase I is commonly used to remove template DNA after in vitro transcription and to remove DNA contamination from total RNA preparations (especially from transfected cells that may contain plasmid DNA). It can be used Used in ribonuclease protection assays, cDNA library shrinkage, and RT-PCR. For maximum activity, DNase I requires divalent cations (Mg²⁺ and Ca²⁺, approximately 5 mM and 0.5 mM, respectively), and the optimal pH is 7.8.

DNase I (without RNase) outperforms competitors
Quoted from a research report by BioTechniques (Matthews et al., 32: 1412-1417, 2002) compared RNase contamination in DNase I reagents from Sigma, Roche, Applied Science, Qiagen, and Ambion. The results show: "Except for Ambion™'s RNase-free DNase I, the integrity of the cRNA in the in vitro transcription reaction was damaged and was still contaminated by DNA. Ambion™'s DNase was used for the rest of the cRNAs that required DNase digestion. experiment of…". Ambion™ DNase I has been tested for RNase contamination and protease activity. Human genomic DNA was digested, and the undigested DNA was subjected to quantitative real-time PCR to determine functionality.

Unit Definition
One unit refers to the amount of enzyme required to completely degrade 1 µg of DNA within 10 minutes at 37°C, equivalent to 0.04 Kunitz units.

Supplementary Products
If you need an alternative to bovine DNase I, please consider recombinant DNase I (Cat. No. AM2235). For more active, salt-tolerant DNase, see TURBO™ DNase products (Cat. Nos. AM2239 and AM2238).