RNASE DNASE-FREE

General description

Pyrimidine-specific endoribonuclease that acts on single-stranded RNA. RNase, DNase-free, is a heterogeneous mixture of ribonucleases that has been prepared free of deoxyribonuclease activity according to the current Quality Control procedures. RNase, DNase-free, is particularly well suited for use in DNA isolation procedures. Before use, most RNase preparations must be boiled to remove DNase activity. This preparation of RNase does not need to be boiled; it can be used directly from the vial.

Application

RNase, DNase-free, efficiently removes contaminating RNA from plasmid or genomic DNA preparations.

Unit Definition

One Kunitz unit is the amount of enzyme that causes a decrease in absorbance of A₀ to A₁ within one minute under the assay conditions. A₀ to A₁ corresponds to the total conversion, A₁ being the final absorbance.
One unit produces a decrease in absorbance at 260 nm, which is equivalent to a total conversion of RNA to oligonucleotides in one minute at +25 °C.

Physical form

Solution, 500 μg/ml, in 10 mM Tris-HCl, 5 mM CaCl₂, 50% glycerol (pH 7.0).

Preparation Note

Working concentration: The optimal working concentration for RNase, DNase free, is 2 to 5 μg/ml. The reaction volume will vary for different applications. Some suggested guidelines are given below:

1. For small-scale isolation of plasmid DNA ("miniprep" from a 1.5 ml bacterial culture), use 0.5 μl of RNase, DNase-free in a reaction volume of 50 μl.
2. To isolate plasmid DNA from a 100 ml bacterial culture, use 8 μl of RNase, DNase-free in a reaction volume of 2 ml.
3. To isolate genomic DNA from cultured mammalian cells (5 x 10⁷ cells), use 8 μl of RNase, DNase-free in a reaction volume of 2 ml.

Other Notes

For life science research only. Not for use in diagnostic procedures.