Supercoiled plasmid DNA

Prazeres, D.M.F., Schluep, T., and Cooney, C., Preparative purification of supercoiled plasmid DNA using anion-exchange chromatography, ]. Chromatogr. A, 806, 31, 1998. 

Giovanni, R., Freitag, R., and Tertnikova, T. B., High-performance membrane chromatography of supercoiled plasmid DNA, Anal. Chem., 70, 3348, 1998. 

Marrot, L. and Agapakis-Causse, C. (2000) Differences in the photogenotoxic potential of two fluoroquinolones as shown in diploid yeast strain (Saccharomyces cerevisae) and supercoiled plasmid DNA. Mutation Research, 468, 1-9. 

FIGURE 24-13 Relaxed and supercoiled plasmid DNAs. The molecule in the leftmost electron micrograph is relaxed the degree of supercoiling increases from left to right. 

Figure 6.11 AFM images of (left) 1 nM supercoiled plasmid DNA (left) and (right) condensed blobs of 1 nM supercoiled plasmid DNA in the presence of 1 mM of calixarene 6.33a (n = 4). Each image is 2 X 2 pun. (Reproduced by permission of The Royal Society of Chemistry).

Separation of polynucleotides 259 Supercoiled plasmid DNA investigated as model... 

Direct Site-selective Scission of Supercoiled Plasmid DNA... 

Thompson, J. A. (1986). A review of high-performance liquid chromatography in nucleic acids research. HI. Isolation, purification, and analysis of supercoiled plasmid DNA. Bio/Chromatography 1, 74-80. 

Figure 19-6. The H yield function from thin films of (A) double stranded linear DNA, 40 base-pairs, (B) supercoiled plasmid DNA, (C) thymine, (D) ice, and (E) a deoxyribose analog. The zero-count baseline of curves A-D has been displaced for clarity. Part of a single DNA strand is shown in the left corner at the top. The dependence of the magnitude of the II signal from DNA on time of exposure to the electron beam is shown in the insert...

Figure 19-7. Yields of SSBs and DSBs induced by 0-4.2 eV electrons on supercoiled plasmid DNA films. The inset shows the dependence of the percentage of circular DNA (i.e. SSB) on irradiation time for a beam of 0.6 eV electrons of 2 nA...

Little is known about DNA damage by Cr(III) complexes, even though these compounds are considered to be responsible for chromium mutagenicity. The [Cr (phen)2Cl2] Euid [Cr (bpy)2Cl2] complexes are both mutagenic and able to cleave a supercoiled plasmid DNA via ss breaks, whereas [Cr (CN)e] is not mutagenic and is inefficient as a DNA cleaver 162). 

Interest in producing large quantities of supercoiled plasmid DNA has increased as a result of gene therapy and DNA vaccines. Due to the commercial interests in these approaches, the development of production and purification strategies for gene therapy vectors has been performed in pharmaceutical companies within a confidential environment. It is thus important to describe the downstream operations for the large-scale purification of plasmid DNA to attain a final product that meets specifications and safety requuements. " ... 

Figure 8.3. Process flow sheet for the large-scale purification of supercoiled plasmid DNA. Unit operations to be considered during process development are indicated together with with the eliminated impurities [Refs in 415].

Stability Real-time studies in final containers (mainly for supercoiled plasmid DNA) Specifications must be met for entire shelf life Accelerated stability studies at elevated temperature and other strenuous conditions useful and recommended... 

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