Navigation Links
An Animal-Free DNase I

Digestion of DNA to undetectable levels is important in many molecular biology applications. For instance, accurate quantitation of RNA targets by RT-PCR requires the removal of contaminating genomic DNA targets. In vitro transcribed RNA is also frequently treated with DNase to remove template DNA in both research and pharmaceutical applications. Ambion now supplies a recombinant DNase I that is prepared in a host with little to no RNase activity. The host is non-animal derived and the enzyme is purified through a process devoid of any animal byproducts.

Isolating RNase-free DNase I is a Challenge
DNase I has historically been prepared from bovine pancreas, one of the richest sources of RNase activity (~1 mg RNase A per gram of tissue). Therefore, it is often hard to obtain DNase I sufficiently free of RNase that it will not compromise RNA analysis experiments. Providing a high quality, RNase-free DNase I is very important to Ambion. This is borne out in a recent Biotechniques article (Matthews et al, 2002) that compared several different manufacturer's DNase I products (see sidebar at right).

A Pure Source of DNase I
Ambion employs stringent purification protocols and qualifies our bovine-derived DNase I at concentrations 5X or greater than that recommended for use. Now Ambion goes a step further by providing an alternative to bovine DNase I, recombinant DNase I (rDNase I), that further eliminates residual RNase and other copurified contaminants. rDNase is a highly purified product derived from cloned bovine DNase I. The rDNase I is prepared in a host that has RNase levels that are 1 x 107 fold lower than bovine pancreas.

Safety of biological products is also an emerging issue. Eliminating animal tissues and animal-derived components from the production process prevents potential transmission of pathogens. Materials derived from bovine sources are of special concern, due to known transmission of bovine spongiform encephalopathy (BSE) to humans via ingestion of cow products. Regulatory agencies are increasingly restrictive in this regard, prompting the pharmaceutical industry to remove high risk raw materials from manufacturing. Ambion's rDNase I now addresses these issues by providing a recombinant replacement for pancreatic bovine DNase I.

rDNase I Performance
Ambion's rDNase I meets or exceeds the performance of native bovine DNase I. It digests DNA to oligonucleotide-sized products or shorter. Yet its reaction kinetics are identical to that of native DNase I. Thus, rDNase I can be directly substituted for native DNase I with equivalent units.

The recommended reaction conditions are the same as Ambion's standard DNase I. Incubate 1-2 U of rDNase I per 1 g DNA for 30 min at 37C in a buffer consisting of 10 mM Tris-HCl, pH 7.5, 2.5 mM MgCl2, 0.5 mM CaCl2.

Quantitative Removal of Contaminating DNA
To demonstrate the efficiency of rDNase I in removing residual DNA, we measured genomic DNA contamination by real-time PCR before and after DNase I treatment. A total of 0.5 g of human genomic DNA was incubated in 50 l, and digested with 2 U of DNase I or rDNase I in a volume of 50 l for 30 min at 37C. One-tenth of this reaction volume (equivalent to 50 ng genomic DNA) was added to a 25 l real-time PCR reaction. The efficiency of DNA degradation was monitored by comparing cycle thresholds (Ct), with and without DNase digestion. As shown in Figure 1B, both DNase I and rDNase I shifted the real-time PCR signal by an average of 13.4 Ct's, or about 11,000-fold, to less than a single copy genome equivalent (~2 pg genomic DNA).

Figure 1. Real-time PCR of Genomic DNA Samples Treated with rDNase I vs. Bovine Pancreatic DNase I. (A) Standard curve generated with 10 fold serial dilutions of human genomic DNA ranging from 100 ng to 10 pg using an ABI 7900 real-time PCR machine. The target amplified was human GAPDH. (B) GAPDH was amplified from three human genomic DNA samples (0.5 g), either treated with DNase I (Ct=36.1), treated with rDNase I (Ct =36.9), or untreated (Ct= 23.1). The two DNase I treatments gave essentially identical results and were therefore averaged and compared to the untreated sample. The Ct of the averaged DNase I treatments vs. untreated human genomic DNA was 13.4.

Lack of RNase Activity
Since rDNase I is derived from a substantially "cleaner" source than pancreatic DNase I, the enzyme can be more readily purified to a RNase-free state. Although the recommended usage conditions for DNase I rarely require more than 2U per reaction, rDNase I passes Ambion's stringent RNase contamination quality control assay using 10 times as much enzyme for a 32-fold longer incubation! This result means that rDNase I is qualified RNase-free at 320 times typical usage conditions, creating an unsurpassed margin of safety for every application.

back to top

Ordering Information
For prices and availability, please contact our Customer Service Department.
Cat# Product Name Size 2235 Recombinant DNase I (RNase-free) 1000 U


Page: All 1 2 3 4

Related biology technology :

1. The Worlds Best DNase Improved TURBO DNA-free
2. TURBO DNase: Hyperactive, Salt Tolerant DNase
Post Your Comments:

(Date:11/24/2015)... Calif. , Nov. 24, 2015 Cepheid ... will be speaking at the following conference, and invited ... New York, NY      Tuesday, December 1, 2015 ... New York, NY      Tuesday, December 1, 2015 ... Jaffray Healthcare Conference, New York, NY ...
(Date:11/24/2015)... , Nov. 24, 2015 /PRNewswire/ - Aeterna Zentaris ... of IIROC on behalf of the Toronto Stock Exchange, ... release there are no corporate developments that would cause ... --> --> About Aeterna ... . --> Aeterna Zentaris is a ...
(Date:11/24/2015)... LEXINGTON, Massachusetts , November 24, 2015 ... Officer, will participate in the Piper Jaffray 27 th Annual ... on Tuesday, December 1, 2015, at 8:30 a.m. EST (1:30 p.m. ... Poulton , Chief Financial Officer, will participate in the Piper Jaffray ... City , NY on Tuesday, December 1, 2015, at 8:30 ...
(Date:11/24/2015)... ... November 24, 2015 , ... In harsh industrial processes, ... for in-line sensors can represent a weak spot where leaking process media is ... retractable sensor housings , which are designed to tolerate extreme process conditions. They ...
Breaking Biology Technology:
(Date:11/18/2015)... --> --> ... report titled  Gesture Recognition Market - Global Industry Analysis, ... to the report, the global gesture recognition market was valued at ... US$29.1 bn by 2021, at a CAGR of 20.3% ... dominated the global gesture recognition market in ...
(Date:11/16/2015)... Nov 16, 2015  Synaptics Inc. (NASDAQ: ... solutions, today announced expansion of its TDDI product ... touch controller and display driver integration (TDDI) solutions ... These new TDDI products add to the previously-announced ... TD4302 (WQHD resolution), and TD4322 (FHD resolution) solutions. ...
(Date:11/10/2015)... , Nov. 10, 2015  In this ... the basis of product, type, application, disease ... in this report are consumables, services, software. ... are safety biomarkers, efficacy biomarkers, and validation ... report are diagnostics development, drug discovery and ...
Breaking Biology News(10 mins):