重组脱氧核糖核酸酶 I（无动物、无蛋白酶和无核糖核酸酶）

Deoxyribonuclease I, Recombinant (Animal-Free, Protease and RNase Free) contains 10,000 units and is sensitive to denaturation. Mix by gently inverting the tube. Do not vortex. It is recommended to reconstitute with a buffer compatible with the intended assay. Vials should be brought to room temperature prior to opening and they should not be opened in humid areas.

Deoxyribonuclease I, Recombinant (Animal-Free, Protease and RNase Free) is a lyophilized powder that contains glycine as a stabilizer. Store at 4ºC and protect from moisture. This product is stable for 12 months when stored at 4ºC. Once in solution, store at -20ºC. Aliquot to avoid multiple freeze/thaw cycles.

One Kunitz unit digests 1 mg of calf thymus DNA in 10 minutes at 37ºC in 50 mM Tris, 1 mM Mg²⁺, 1 mM Ca²⁺, pH 7.8. The correlation of digestion units with Kunitz units can change in other buffer systems.

Deoxyribonuclease I, Recombinant (Animal-Free, Protease and RNase Free), also known as DNase I, is isolated from bovine pancreas and produced recombinantly in Pichia pastoris. This endonuclease cleaves DNA to produce products with 5'-phospho and 3'-hydroxy ends (1). DNase I is dependent on calcium ions (Ca²⁺) and activated by magnesium ions (Mg²⁺) and manganese ions (Mn²⁺). The Ca²⁺ work to maintain the enzyme conformation and the Mg²⁺ and Mn²⁺ help to catalyze the cleavage of phosphodiester bonds (2). In the presence of Mg²⁺, DNase I cleaves each strand of dsDNA independently and at random. In the presence of Mn²⁺, DNase I cleaves each strand of dsDNA at approximately the same site. This enzyme can be used to remove genomic DNA from RNA preparations prior to RT-PCR, to degrade DNA templates after transcription reactions, and to remove unwanted DNA from samples prior to Northern blotting (3-5). DNAse is used in tissue dissociation protocols to digest any DNA that may be present due to cell damage.