title: Simian virus 40 DNA extracted from infected cells with sodium deoxycholate no longer reflects its in vivo superhelix density.
abstract: When simian virus 40 DNA is extracted from infected cells with low concentrations of sodium deoxycholate, which selectively extract non-encapsidated simian virus 40 DNA, the DNA has a lower average number of superhelical turns than the DNA extracted from purified viral particles. During extraction, a partial deproteinization of the DNA by a concentration of detergent that did not inactivate a nicking-closing activity led to the removal of some superhelical turns. The DNA extracted in this way no longer reflected its in vivo number of superhelical turns.
mesh_terms: D004278:DNA, Superhelical / Q000032:analysis* / Q000302:isolation & purification; D004279:DNA, Viral / Q000032:analysis* / Q000302:isolation & purification; D003840:Deoxycholic Acid / Q000494:pharmacology*; D004996:Ethidium / Q000494:pharmacology; D009690:Nucleic Acid Conformation / Q000187:drug effects; D013539:Simian virus 40 / Q000032:analysis*
chemical_list: D004278:DNA, Superhelical; D004279:DNA, Viral; D003840:Deoxycholic Acid; D004996:Ethidium