title: A rapid method for the purification of extrachromosomal DNA from eukaryotic cells.
abstract: A simple and efficient procedure to purify the low molecular weight extrachromosomal DNA from eukaryotic cells is described. Gentle lysis of cells with urea and sodium dodecyl sulfate in 0.24 M phosphate buffer (pH 6.8) is followed by the removal of high molecular weight bulk DNA by centrifugation. Protein and RNA are removed from the supernatant by hydroxyapatite chromatography in urea/phosphate buffer. Urea is then removed with 0.15 M phosphate buffer and the extrachromosomal DNA, virtually free from protein and RNA,  is finally eluted in 0.5 M phosphate buffer. The procedure allows the recovery of about 99% simian virus 40 (SV40) DNA from infected monkey kidney cells in the extrachromosomal fraction. In normal mouse, monkey, andhuman cells, approximately 1% of total cell DNA appears to be extrachromosomal.
mesh_terms: D002460:Cell Line; D002499:Centrifugation, Density Gradient; D002845:Chromatography / Q000379:methods; D004279:DNA, Viral / Q000302:isolation & purification*; D006882:Hydroxyapatites; D012367:RNA, Viral / Q000302:isolation & purification; D013539:Simian virus 40; D014764:Viral Proteins / Q000302:isolation & purification
chemical_list: D004279:DNA, Viral; D006882:Hydroxyapatites; D012367:RNA, Viral; D014764:Viral Proteins