Merck, D1501-1G, Deoxyribonucleic acid sodium salt from calf thymus

General description
λmax₂₅₉ nm (100 mM phosphate buffer, pH 7.0).
DNA from calf thymus is 41.9 mole % G-C and 58.1 mole % A-T.1 An OD of 1.0 at 260 nm corresponds to ~ 50 μg of double-stranded DNA.
Application
Calf thymus DNA (CT-DNA) is a natural DNA widely used in studies of DNA binding anticancer agents and DNA binding agents that modulate DNA structure and function. Calf thymus DNA is also used in physicochemical studies of DNA behavior in solution.
Physical form
fibrous preparation
Preparation Note
Solutions of DNA have been stored successfully for several months at 4 C, pH 7.5-8, in 10 mM Tris with 1 mM EDTA and without a bacteriostatic agent. At low concentrations (μg/ml) DNA tends to absorb onto the surfaces of plastic tubes. It is not recommended to store DNA in highly alkaline solutions since DNA tends to degrade at alkaline pH greater than 8.0.
This product can be dissolved at 2 mg/ml in water. To reduce further shearing of the DNA, no sonication or stirring should be used. Gentle inversion overnight at 0-4 °C is recommended to completely solubilize the DNA. The presence of 1 mM EDTA is recommended to prevent nucleases from degrading the DNA.
This product is extracted using a method that causes shearing yielding a highly polymerized mixture of double and single stranded DNA . However, double stranded DNA is the predominant form.
This product is prepared from calf thymus tissue of unspecified gender.
Analysis Note
"Highly Polymerized"