Description

• General description: Escherichia coli strain B is most widely studied DNA after k-12. The genomes of E coli strain B and k-12 show differences in the IS sequence elements. Strain B have B-islands and express O-specific side-chain LPS.[1] The product is unsheared genomic DNA.
• Specificity: 50% GC; Tm = 90.5 °C
• Application: The DNAs are particularly useful for genomic analysis, including PCR, library construction in bacteriophage λ, and in heterologous pre-hybridization and hybridization protocols. Deoxyribonucleic acid sodium salt from Escherichia coli strain B has been used for:PCR reactions of genomic DNA of Gardnerella vaginalis[2] nick translation and radiolabeling of dNTP[3]generating standard curve for 16S rDNA quantification[4] transfecting neutrophils[5] testing the extraction methods[6]
• Unit Definition: One unit will yield an A260 of 1.0 in 1.0 ml of 1 mM Tris-HCl, pH 7.5, with 1 mM NaCl and 1 mM EDTA (1 cm light path).
• Preparation Note: Purified by anion exchange chromatography, dialyzed against a solution of 1 mM sodium chloride, 1 mM EDTA and 1 mM Trizma HCl, pH 7.5 and lyophilized at a concentration of approx. 2 units per mL. Approx. 20 A260 units per mg DNA. % GC is the percentage of G/C base pairs. Tm is the temperature at the midpoint of the thermal denaturation profile.
• Analysis Note: Analyzed by gel electrophoresis and visualization after ethidium bromide staining, with single predominant band of 45 kB or greater.
• Other Notes: DNA in solution will reanneal on standing at room temperature so it is recommended to boil the solution for 10 minutes and then cool on ice for at least 5 minutes prior to use.