Isolation of plasmid DNA

Most plasmids are topologically closed circles of DNA. They can be separated from the bulk of the chromosomal DNA by virtue of their resistance to alkaline solution. The double-stranded stmcture of DNA is denatured at high pH, but because the two strands of the plasmid are topologically joined they are more readily renatured. This property is exploited in rapid procedures for the isolation of plasmid DNA from recombinant microorganisms (5,6). 

Isolation of plasmid DNA, transformation, transfection and cloning procedures were performed using standard techniques (Sambrook et ut/., 1989). 

Microscale Isolation of Plasmid DNA by Alkaline Lysis (Bimboim, 1983)... 

The isolation of plasmid DNA by the boiling method (part B-l) yields a product of sufficient purity for analysis in Experiments 14 and 15. The procedure works well with chloramphenicol-amplified or untreated cell cultures. If cell cultures are available, the isolation method... 

B. Isolation of Plasmid DNA B-1. Large-Scale Boiliug Method... 

H. Bimboim, Methods EnzymoL 100, 243-255 (1983). A Rapid Alkaline Extraction Method for the Isolation of Plasmid DNA. ... 

The range of the (molecular) size of the analytes usually exceeds that which can be determined by classical laboratory analytical methods such as size exclusion chromatography, etc. [351]. Reports on investigated substances are widespread and cover applications such as the separation and characterization of proteins [450] and enzymes [240, 241], of viruses [132], the separation of human and animal cells [50, 51], the isolation of plasmid DNA [367], and the molecular weight and particle size distribution of polymers [216,217]. The approach is relatively new in biotechnology therefore, practical experiences are not yet abundant. Langwost et al. [229] have provided a comprehensive survey of various applications in bio-monitoring. 

Examine the procedure described in Experiment 21 for the isolation of plasmid DNA from bacteria. It is very different from the procedure used to isolate chromosomal DNA in this experiment. Could it be used to isolate chromosomal DNA from bacteria Why or why not Explain why such different procedures are used for isolating these two types of DNA. 

Many procedures have been developed for DNA isolation, differing according to the scale of the operation, the nature of the biological source material, and the nature of the DNA, particularly whether plasmid or genomic (Ausubel et al. 1989 Maniatis et al. 1989 Harwood 1996). As a prototype procedure, we first describe the small scale isolation of plasmid DNA from E. coli by the alkaline lysis method. This miniprep procedure starts with E. coli cells from a few ml of culture which have... 

Isolation of plasmid DNA from the protoplasts of P. oryzae and D. oryzae For the isolation of plasmid DNA in p. oryzae, the method of Takai et al. (28) was followed and for D. oryzae Kistler and Leong s(29) method was followed. 

The extraction and isolation of DNA and RNA from biological and environmental samples is an important but often overlooked aspect of detection schemes. The prevailing dogma has been to recover as much nucleic acid as possible by time-tested methods such as phenol-chloroform extraction of RNA [81], alkaline lysis/mini-prep isolation of plasmid DNA [82], or choosing one of a wide variety of... 

Ribeiro, S.C. et al.. Isolation of plasmid DNA from cell lysates by aqueous two-phase systems. Biotechnology and Bioengineering, 2002 78(4) 376-384. 

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