Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-7-14
pubmed:abstractText
During the course of gene therapy experiments in rodents, using intramuscular injections of plasmid DNA derived from Escherichia coli, we noted dose-related toxicity. This observation prompted a search for possible contaminants of DNA samples. We used the highly specific and sensitive limulus amoebocyte lysate assay (LAL), to monitor endotoxin bioactivity in DNA samples, and found plasmid DNA derived from standard E. coli bacterial strains, using traditional DNA isolation protocols, to be heavily contaminated with endotoxin, or lipopolysaccharide (LPA). Standard DNA isolation procedures resulted in the copurification of up to 500 micrograms/ml of LPS. LPS is a potent inducer of cytokines and other inflammatory mediators, and may complicate the use of naked DNA in gene therapy. The copurification of endotoxin with plasmid DNA also has important implications for in vitro transfection studies and microinjection of DNA into embryos. A simple and efficient protocol to reduce LPS contamination of plasmid DNA was developed. The conversion of intact bacteria to spheroplasts prior to the isolation of plasmid DNA, incubation with lysozyme, treatment with the detergent n-octyl-beta-D-thioglucopyranoside (OSPG) and polymyxin-B (PMB) chromatography, allowed the isolation of plasmid DNA containing less than 50 ng/ml LPS. This represents a 10,000-fold reduction in LPS contamination, compared to conventional methods of plasmid DNA purification, avoids potentially toxic reagents such as ethidium bromide, and produces a higher yield of plasmid DNA.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1043-0342
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
317-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7779915-Animals, pubmed-meshheading:7779915-Chromatography, Agarose, pubmed-meshheading:7779915-DNA, pubmed-meshheading:7779915-Disease Models, Animal, pubmed-meshheading:7779915-Encephalomyelitis, Autoimmune, Experimental, pubmed-meshheading:7779915-Endotoxins, pubmed-meshheading:7779915-Escherichia coli, pubmed-meshheading:7779915-Female, pubmed-meshheading:7779915-Gene Therapy, pubmed-meshheading:7779915-Humans, pubmed-meshheading:7779915-Immunoglobulin M, pubmed-meshheading:7779915-Limulus Test, pubmed-meshheading:7779915-Lipopolysaccharides, pubmed-meshheading:7779915-Mice, pubmed-meshheading:7779915-Plasmids, pubmed-meshheading:7779915-Polymyxin B, pubmed-meshheading:7779915-Rats, pubmed-meshheading:7779915-Rats, Sprague-Dawley, pubmed-meshheading:7779915-Spheroplasts
pubmed:year
1995
pubmed:articleTitle
Bacterial lipopolysaccharide copurifies with plasmid DNA: implications for animal models and human gene therapy.
pubmed:affiliation
Department of Medicine, University of California, San Diego, La Jolla 92093-0663, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't